Fandom/Series: X-Files, M/K/ofc
Title: Sinful
Author/Pseudo: Orithain
Rating: NC-17 for explicit m/m/f sex
Archive: Yes, anywhere as long as you tell me.
Series/Sequel: This might be the first in a series, I haven't decided yet.
Author Email: orithain@aol.com
Disclaimer: They're not mine, and if you sue, all you'll get is debts!
Story Summary: Mulder's bed is getting very crowded.

Thanks to Nic and Aries for comments and encouragement. If you like it, thank Nic, I had no intention of writing in another fandom. If you don't, :::shrug:::
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The sound of the apartment door opening woke Sin from a sound sleep. No matter how secure she felt in Mulder's bed, some habits couldn't be broken. Before she could roll out from under Mulder's arm, she saw a dark shape appear in the bedroom doorway. Cursing herself for leaving her weapons in the living room, Sin slipped out of the bed. She had to distract the intruder from her sleeping lover.

She couldn't believe she had been stupid enough to let herself relax her guard just because she was finally in Fox Mulder's bed. She'd learned to stay alert almost before she could talk, a side effect of being a member of an extremely wealthy family, not to mention one where nearly ever member had been at least peripherally involved in the intelligence community at some time in their lives. But Mulder got past her guard, and she'd lost herself in the pleasure of being with him, a mistake that just might cost them both their lives.

At that moment the cloud cover cleared, and bright moonlight shone into the room. She found herself staring into a pair of shocked green eyes. Recognizing the face, Sin wondered just what else Mulder *hadn't* told her about his relationship with his ex-partner Alex Krycek. Judging by the glare coming her way from narrowed eyes, Krycek and Mulder were still on very...friendly...terms. Mulder had been honest with her, telling her he was in love with someone else; he just hadn't bothered to mention that it was Alex Krycek. Not wanting to wake Mulder, Sin indicated to Krycek that they should go into the living room with a silent motion of her head. At his nod, she preceded him out of the room, stopping only long enough to grab Mulder's discarded shirt and shrug it on.

<Who the fuck is this?> Alex wondered. He knew Mulder was bi, but he didn't expect to find a woman in bed with his lover when he stopped by. So what if it had been nearly seven months since he had been able to get in touch with Mulder. Not wanting to be interrupted, Krycek pulled the bedroom door closed behind him as he followed the petite blonde into the living room.

Flicking on the desk lamp, Sin turned to face the angry man holding a gun on her. "So you're Alex Krycek."

He'd had enough. "Who the fuck *are* you?"

"Tamsin Soldat. Sin." Alex blinked at the name. He'd heard it during his months in Europe. Sin was the name of an American variously rumored to work for the CIA, the NSA or any one of a dozen other agencies. He'd thought she was apocryphal, just another story made up to send members of the intelligence community on a wild goose chase. Looking at the slight, 5'1" blonde who couldn't have been more than 23, Krycek wondered how she could have accomplished even a fraction of what she was rumored to have done.

Accustomed to the reaction, Sin answered the question. "No one expects someone who looks like me to be dangerous. I take advantage of that fact...as you can see."

Alex wondered when she had picked up the stiletto currently pressing against his throat and vowed never to underestimate her again...if he survived the next few minutes. Although he still had his gun, even if he shot her, she'd slit his throat before she died.

With a faint smile, Sin withdrew the knife and curled up on the end of the couch. "I think we have something in common, Alex. You don't mind if I call you Alex, do you? It seems kind of pointless to stand on formality at this point."

Shaking his head in bemusement, Krycek holstered his gun and sat down at the opposite end of the couch. Sprawling back comfortably, he looked at her. "So is this where you tell me that he's yours and never to bother him again?"

She snorted. "Hardly. You and I both know that Fox loves you. But, he loves me too. I think he needs both of us."

"Huh?"

"Come on, keep up with me here, Alyosha, moi drug. Mulder told me he was in love with someone else; he just didn't say who. I assume you've been away for a while because he was absolutely miserable for several months before deciding to give us a try."

"And now that I'm back?" Alex couldn't believe the surreal conversation he was participating in.

"I'm willing to share him with you." Sin wouldn't meet Krycek's eyes. "I don't want him hurt, and forcing him to choose between us, even though you'd win, would hurt him."

Krycek was startled to hear her say Mulder would choose him, but she was right. If Mulder trusted her enough to sleep soundly with her in his bed, she was important to him. Mulder didn't have many people he could trust in his life, and Alex didn't want to take one away from him. Hell, that was why they'd kept their relationship secret, so as not to upset Scully.

"Hey, Alex, you still awake?"

He started. "Yeah, sorry. So what, you get him evenings and alternate weekends, I get him for the summer and holidays?"

Sin grinned at him. "Hardly. I was thinking of something more along the lines of...umm, an Oreo cookie."

"A *what*?"

"You know, two similar hard outer shells constantly surrounding a sweet center."

"Lady, you're nuts."

"Okay, so that was reaching a bit. Gimme a break, it's 3:00 in the morning and I'm hungry! This is kind of what I had in mind." With that, Sin leaned forward and kissed him.

Alex was startled by the heat generated by that kiss. He found himself holding Sin in his lap as he deepened the kiss. He pulled back to stare in shock.

"Now insert Fox in the middle of that, and what do you get?" Sin sounded like a teacher coaxing a slow student toward the right answer.

"A nuclear meltdown! I feel like I walked around the corner and through the looking glass!"

"Compare me to the Queen of Hearts and you're a dead man." Sin grinned while she said it and was still in his lap, so Alex didn't worry too much. "Seriously, I really do think he loves both of us, and I don't see any reason why the three of us can't work something out." She squirmed a little to get comfortable. "And you don't seem to have any objections."

"So now what?"

"Now we go back to bed, and you can let Mulder know you're back."

Krycek looked at her hesitantly.

"I intend to be right there. *Mulder* has no idea what I'm capable of, so if he woke up and found you there and me nowhere to be seen, he'd probably think you'd killed me. Besides which, I'm looking forward to this."

Alex laughed, standing up with Sin still in his arms. He grinned at her, "I finally found a woman the right size to do a Rhett Butler imitation with."

Sin jabbed him in the ribs, but they were both grinning as Alex carried her into the bedroom.

Placing her gently on the bed, Alex quickly stripped off his clothes under her appreciative gaze and slid in on Mulder's other side. On some level Mulder must have been aware of Krycek's presence since he turned into the other man's embrace. Alex drew his lover tightly against himself, tangling their legs together and leaned in for a kiss.

Fox gradually woke up to the familiar taste of Alex. Still half asleep he smiled and opened his mouth more, enticing Alex in. By the time he woke up enough to wonder where Alex suddenly came from and to remember Sin's presence when he fell asleep, he was already hard. Realizing the incongruity of the situation, Mulder pulled back with a garbled exclamation, his eyes widening in disbelief when he saw Sin reclining against the pillows.

Sin grinned when she saw Mulder notice her and waved.

Alex bit Mulder's shoulder to get his attention.

Mulder stared wildly from one pair of green eyes to the next.

"Something wrong, Fox?" Sin wanted to know.

"Aren't you glad to see me?" Alex sounded hurt.

"You...I...we...how...when...Alex!" Mulder was incoherent.

Alex sighed, realizing he was going to have to explain everything to Mulder's satisfaction before he could get on with the important activities. "I'm sorry I didn't get in touch with you for so long, but I was being closely monitored. It would have been too dangerous for you. I knew you might think I was dead, but I didn't have a choice. I came back as soon as I could." Glancing at Sin out the corner of his eye, Alex decided to see just how accurate her analysis of Mulder was. "Or don't you want me here anymore?"

Mulder sputtered. "Of course I want you here. I love you, Al..." he trailed off, suddenly remembering Sin's presence. Looking over at her miserably, Fox was stunned to find her smiling at him.

Sin leaned forward to kiss him lightly, trailing a hand over Alex's shoulder at the same time. "You seem to forget, you told me you were in love with someone. I don't see why all three of us can't be very happy together."

Mulder stared, stunned into speechlessness.

Deciding that there had been enough talk for the moment, Alex kissed Mulder again, drawing a response from the older man. He wrapped his naked body around the other man's, pressing their erections together, while he tasted every inch of Mulder he could reach.

Fox was moaning by the time Alex worked his way back to his mouth. The younger man grinned before stopping the sounds with his own lips, tangling his tongue with his lover's.

Fox was twisting wildly beneath Alex and wondered vaguely when Krycek had rolled on top of him, pinning him down. He desperately wanted to touch the other man, but Alex had his wrists trapped in his own hands and seemed to have no intention of releasing him any time soon.

Meanwhile Alex had turned his attention to Fox's nipples, sucking them into hardness and nipping at them while maintaining the contact between their cocks. He wanted Fox to come quickly, then he would take his time with the older man. He glanced up at Sin to see her reaction to all of this and found her watching them closely, breathing hard.

Sin was amazed at the beauty of the two men before her and thankful that they were hers. She could almost see the love between them, and she intended to be part of it. She met Alex's eyes and smiled, eager to see them love each other.

Alex was distracted by Sin's smile and the arousal he could see in her green eyes. He unintentionally relaxed his grip on Mulder slightly, and the other man took immediate advantage.

Mulder twisted free of Alex's grasp, rolling them both over so that he ended up behind Krycek, both of them on their sides facing Sin. Mulder slid his arms around his lover, pinching his nipples lightly to hear the breathy gasp he loved. His other hand stroked Alex's flank while he fitted himself to the younger man's back. He looked over at the night table, trying to see what was on it without moving away from Alex.

Sin saw Mulder's searching glance and realized what he must be looking for. She pulled the tube of lubricant out of the drawer and pressed it into Mulder's hand.

Mulder's eyes flashed up to meet hers, and he was as stunned as Alex had been by what he saw there: arousal, interest and what looked like love directed at both of them. Working almost on autopilot, he flipped the cap off and squeezed the gel out onto Alex's hip. Scooping up a healthy amount, he applied it to Alex lingeringly, slowly stroking it around and into the ring of muscle so eagerly waiting for him. When he had worked one, then two, then three fingers into his lover, and Alex was pushing back on those fingers, whimpering for more, Mulder withdrew and smoothed the remaining lube onto himself. He was so sensitive that the slight touch almost made him come.

Drawing a deep breath, Fox thought unsexy thoughts: Cancer Man, nuns, AD Skinner, wet dogs, Scully, anything to calm himself slightly. When he'd regained a little control, Fox slid the head of his cock into his lover, stopping when he heard Alex moan.

"No! Don't stop. I want you inside me; I need you inside me. Please! Oh god...Fox...that feels so good; you feel so good. Harder...more...please!" Alex nearly screamed when Fox grasped his cock with one hand while the other hand slanted up across his chest and shoulder, drawing him back tightly against his lover. Fox was impossibly deep inside him while he was stretched out along the length of Mulder's body. When Mulder released his cock to grasp his hip while thrusting into him, Alex cried out in protest while his eyes flew open.

He realized that Mulder had positioned them so that Alex was stretched open and vulnerable, displayed like an offering before Sin. After one look into her eyes that practically glowed with heat, Alex whimpered and shut his own eyes again. He pushed back on Mulder's cock in his ass, trying to force him ever deeper.

Suddenly Alex's eyes flew open again as he felt his cock engulfed by moist warmth. Looking down, he saw Sin's blonde head at his groin and watched as she pulled back, releasing him from her mouth with one last lick. Alex whimpered when she let her hair fall over his aching cock, teasing him with the light touch. He thrust forward trying to get back into her mouth, then pushed back to recapture Mulder's length inside him. He reached out intending to pull her to him, but Mulder grabbed his hand, drawing it down to rest against his hip, and his other hand was trapped under his body. Alex growled in protest, wanting the freedom to touch either of his lovers, but for tonight Alex Krycek was not in charge.

Sin teased him for what seemed an eternity, her tongue darting to lick at him here and there, with occasional nibbles on especially succulent bits. Alex thought he would go mad when she latched onto a nipple, licking and biting it while Mulder continued to play with its mate. Still held tight in Mulder's grasp, Alex could do nothing to hurry either of them along. In fact, Mulder had stopped thrusting inside him and now simply filled him, refusing to move or to let Alex move. Alex knew he wanted to; he could feel Fox trembling against him, but he and Sin (and wasn't she well named!) seemed determined to drive him into a frenzy.

Eventually Alex abandoned pride, his only concern to get relief. He begged; he pleaded and cursed. Tears of sexual frenzy ran down his face, and Sin's only reaction was to lick them away, being careful to keep her body from touching his aching cock. She kissed him deeply, anxious to imprint his taste on a subconscious level. She drew away and caught his throat in her teeth, sucking and biting him, a female animal marking her mate. Alex barely remembered noticing a matching mark on Mulder earlier.

Mulder remained still behind and inside Krycek, his whole body quaking with the desire to thrust and claim his mate. But he was enjoying what Sin was doing to Alex; usually the younger man controlled their lovemaking just by the force of his personality. Seeing Alex's reactions, Mulder made a mental note to drive Alex into a sexual frenzy more often; it stripped away all the younger man's defenses, leaving him open. For probably the only time since the whole Duane Barry fiasco, Alex looked his age, young and vulnerable. Mulder leaned further over Alex's shoulder to catch Sin in a kiss.

Alex moaned, seeing them kiss frantically while surrounding him.

Sin had been watching Alex closely and decided it was time to give him some relief. Moving in so she lay on her side facing Alex, she draped one leg over his and Fox's hip. Then she took his cock in her hand, gripping him only enough to position him, and suddenly sheathed him. What she had been doing had excited her nearly as much as Alex, so he slid in easily.

At the exquisite sensation of Sin's internal muscles clutching him, Alex exploded, crying out incoherently.

Catching Mulder's eye, Sin shook her head when she saw him tense in anticipation of finally thrusting into his lover's willing body. Mulder caught his lip between his teeth but held still, holding off his orgasm by sheer force of will while Alex's body convulsed around him.

Alex lay panting and boneless, amazed by the force of his orgasm and wondering if he would survive. He didn't particularly care. After a little while he realized that Mulder was still hard inside him and Sin's internal muscles were massaging his cock, keeping him hard inside her. After the explosion of pleasure that had just wracked his body, Alex couldn't believe he still wanted more, but he could feel his hips twitching involuntarily in reaction to Sin's movements. He started to thrust into her, feeling Mulder's cock slide out of his ass, then pushed back onto Mulder, nearly coming out of Sin. Both of his lovers lay still, letting him drive all three of them to pleasure. Alex could feel Fox's mouth on the back of his neck, leaving another mark on him, and he caught Sin's shoulder between his own teeth, marking her in turn. Soon the total stimulation of his body made Alex come again, so hard he thought his spine would break at the strength of the arch he achieved. After waiting so long, Alex's pleasure triggered his lovers', and they tumbled after him into bliss.

Long minutes later Alex found the strength to force his eyes open. He was still inside Sin and Mulder in him, but he could feel both of them softening and knew they would soon separate. He stared at Sin in disbelief. "What the hell was that?"

Sin couldn't help it; she started to laugh. "Do I need to teach you about the birds and the bees?"

Alex could feel Mulder shaking behind him, trying to hold in his own laughter. "Very funny. You know what I meant."

Sin just looked at him.

"I thought the plan was for *us* to love *Mulder*."

"There was a plan? How long was I asleep?" Mulder wanted to know.

"Don't blame me." Sin and Alex both ignored Mulder's interjection. "Talk to Mulder. When he offered you to me like some pagan sacrifice, I certainly wasn't going to refuse!"

Alex remembered that it *had* been Mulder who seized control, and he rolled on to his back to look at the older man. "Just what *was* that all about?"

A shadow passed over Mulder's face briefly. "You made me wonder if you were dead or alive for seven months, Alex. I wanted to make sure that if you left me again, you'd know just what you were leaving behind, you'd still feel me inside you a year from now."

Alex shivered and seized a kiss from Mulder. "God, Fox, don't you know how much I love you? If it were up to me, I'd never spend another day apart from you. But I have enemies, and you have your search for the truth, and it would kill me if someone hurt you because of me." He buried his face in Fox's chest, unwilling for his lover to see his tears at the thought.

Mulder drew Alex up with a hand under his chin. "I can understand that, Alex. Hell, everyone around me seems to be kidnapped or killed! I of all people understand not wanting someone else to pay for your mistakes. But don't you see, I can't live always wondering if you're dead in some alley somewhere, and I'll never know it. I love you too. Stay here with me, with us," Mulder amended with a glance at Sin, who was stroking Alex's shoulder soothingly.

"I wish I could!" Alex burst out. "But you know I can't. If the Consortium didn't get me, Skinner or Scully would!"

Mulder couldn't deny that. After Skinner's actions the night he brought Alex to the AD's apartment, he knew his superior would like nothing better than to tear the younger man into tiny pieces. And Scully blamed Alex for her sister's death.

"Actually, if you really are ready to stay, I can arrange for you to have credentials that'll make anyone think twice about moving against you," Sin offered.

Both men looked at her in disbelief.

"I'm serious. I can get you instated as an ICIN agent," Sin said, mentioning the relatively new but very powerful international intelligence agency. "One of my cousins and her husband are the founders and co-directors. Toren would do it in a second if I asked her. Not to mention that your...talents...would be quite useful to us."

"'Us'?" Mulder repeated. "You work for ICIN?"

"I guess I forgot to mention that, huh?"

"Tammy!"

"By the way, Fox, I know I told you my name was Tammy Martin, but that was just because my real name, Tamsin Soldat, is a little too well known. I *hate* the name Tammy. My name is Sin." Ignoring Mulder's mutters, she turned her attention back to Alex. "So what do you say Alex? Are you ready to try this? I can promise you, no FBI assistant director will argue with ICIN credentials."

Alex stared from Sin to Fox. *Was* he ready to do this? It was more than accepting a job with ICIN, though that alone would change his life. If he stayed he'd be making a commitment to Fox and to Sin. He looked from peridot green eyes to hazel green ones and knew his decision was already made. "I'd like to stay."

"I'll call Toren first thing in the morning." Sin looked down, unable to meet either man's eyes. She took a deep breath and continued, "What about me? Now that you're together, do you want me to disappear?" She had to know.

Both men reached for her, pulling her between them. "I have no idea how I'll explain any of this to Scully," Mulder sighed, "but we're all in this together. Don't you dare try to disappear on us. We'd just have to hunt you down and punish you."

She laughed shakily. "You didn't tell me you were into that kinky stuff, Mulder."

He grinned down at her, and Alex jumped into the conversation, "Would it surprise you to know that *I* have very varied tastes?"

Sin started to laugh in earnest. "Nothing about you, Aleksei Sergei'itch Krycek, would surprise me!"

Alex blinked at hearing his whole name.

Mulder shook his head. "Why do I think that the two of you together are going to be way more trouble than either of you on your own?"

"Because you're a very intelligent man, Fox." Sin grinned up at him, smiling fondly when Alex kissed him over her head.

"I love this woman's height!" Alex exclaimed after releasing Fox's lips.

"That's just 'cause you can grope me and kiss him at the same time without straining yourself," Sin responded dryly.

"A match made in heaven." Alex was almost giddy with the unaccustomed feeling of belonging.

The three fell asleep in each other's arms.

The next morning Mulder kissed each of his lovers lightly before leaving for work, reminding Sin to take care of getting Alex under ICIN's protection. He never noticed that he was whistling cheerfully as he left.

THE END -- OF THE FIRST NIGHT