A/N: sex right out of the gate. BE CAUTIOUS

He had his face between her legs working her to another orgasm when she started to sober up. She knew she was sobering up because she was thinking thoughts again. Not logical thoughts, just random intrusions pulling her up from the deep end of pleasure. Like, how there was no mistaking the sound of cunnilingus for anything else once you'd had it or done it. And like, how fast he'd found her clit. How maybe he'd experimented a lot at the academy. Or some sexy Orion showed him around down there. Orions had like three or something. Did Vulcan women have an analogous organ? They must have. Clitoris and penis usually evolved concurrently. She'd ask him later. He'd know. He was engaged to a Vulcan, after all.

Oh, and yeah, Spock was just a guy cheating on his girlfriend now.

Her sudden searing disappointment in him was profound enough to make him pause. The squelch of his fingers moving in and out ceased. His mouth and tongue left her pussy bereft. "What has happened?"

She propped herself on her elbows and looked down her body at him. Why don't you tell me? But with his face painted in her vaginal fluids it was hard to hold onto the feeling.

She scooted back from the edge of the bed, and made her body a starfish, wide open and ready for whatever came next. He crawled up between her sprawling thighs and wiped his face on them. Nosed her belly button, sat back on his heels. Waiting for direction, for inspiration or, like her, waiting for logic to make a fortuitous return.

But this almost preternatural abidance of his couldn't hide what lurked under the surface. Something she'd noticed earlier in the galley bar, something noticed without actually noting it at the time. A quiet seething something that informed the evening.

Ordinarily, as a friend, she would have asked about it, offered support and advice. But her vagina was not interested in just being friends. Besides, she had her own stuff she was trying not to seethe about.

So, she gave her scientist-brain free rein for a moment, cataloguing physical differences. Longer torso. Larger ribcage. The double-time drumming of his heart. His unflagging, undeterred erection with its exotic coloration and intriguingly shaped head.

She'd need to get up close to investigate properly, trail her gaze over ridges and veins and varying hues like an old-school detective with a magnifying glass. She'd stroke it, not too hard, rub her thumb over the glans, smell and lick and suck and do all the animal things she imagined even Vulcans did in private. Sex was the humbling, messy equalizer across species – regardless of emotional involvement or psychological motivation. She wasn't fooling herself he had none either. They hadn't kissed on the lips since they got here.

She closed her eyes, trying not to catastrophize meaning out of lack. Took a breath and let it out slowly. Then again. There. Almost zen–

Her eyes few open at the sudden jerk of her body. He had her by the calves, tugging her closer. When she was close enough to catch by the wrists, he pulled her into a sitting position. She blinked at him, intrigued, a little annoyed, and then before she could ask what's what, she was scrabbling at his shoulders as he lifted her up and deposited her on his knees.

Her left leg bent awkwardly. She shifted it around his back, heel nestled at the base of his spine. Her right foot came around to join it. Between them, his cock stood like a mountain she'd have to scale to get any closer.

They looked each other in the eyes, gauging their level of commitment to this thing there was no going back from, his expression a sort of grim resolve she tried not to take personally.

"Hello," she said.

A slow blink. "I am going to put my penis in your vagina now."

Well, goddamn. How could a clinical statement of intent sound so sexy?

"Okay," she gulped.

His hands slid from her hips to her buttocks, fingers squeezing and kneading, spreading the cheeks a little as he encouraged her to rise. She braced herself on his shoulders and let him take aim. The tip was right there, kissing her labia. She squirmed, gave a little twist—

A shuddering unsexy grunt came out of her as she sank down and he pushed in. Her vagina spasmed around the shape of him; muscles mapping out this strange new territory before exploring it fully.

He caught and swallowed a sigh, caught her hips again midrise. His forehead pushed against her collar bone, and kept her from moving too soon so it wouldn't be over before it began. That he needed a moment to gain control was a grace note to the sheer wonder of his physical presence in her cabin, on her bed, in her body.

Slowly his grip eased, and she shifted cautiously in his lap. He thrust up. Her breath scattered. They began to bump and bounce and grind in earnest.

Her ears plucked each sound he emitted out of the air like treasure. Roger never seemed to shut up during sex, rattling a stream of delicious filth in every language he knew (and he knew a lot of languages) and much as she loved that, this, with Spock, was delicious in a different way, because each sound was a study in what made it happen and how to make it happen again. Each soft groan, moan, and hiss was a testament to the power her body had to pull them out of him.

He tried to touch every part of her at once, a breast, an armpit, her temples, the ladder of her spine. Knuckles brushed at her swollen clit, then rolled hard against it as they rocked together. She pressed her moaning lips to his throat and worked her way sloppily to his mouth. But when she leaned in to kiss him, he ducked his head. And when he realized what he'd just done, he froze.

She drew back to peer at him. He looked to be in pain, body rigid, furrowed brows a vee over eyes screwed shut.

"Did I do something wrong?" She could hear her voice trying to punch a hole through a fog of oxytocin and alcohol.

"No." He sucked in a cleansing breath, shook himself a little. "No," he repeated, squaring his shoulders. He met her eyes resolutely. "My apologies. We will continue."

But it was the kind of resolve someone might have if they were going into a battle they didn't expect to survive. Melodramatic but troubling.

Soft dread settled under her ribs. She hoisted herself up, feeling the drag on his cock from the inside, like all her juices had suddenly evaporated. "If you're having second thoughts…"

"No. I-I want to do this."

But the want to sounded a lot like have to. Must do.

Christine tipped her head back and examined the ceiling. Her vaginal muscles fluttered and twitched, wanting him back. She sighed. Peeled his thumbs away from where they hooked over her hipbones, pulled up off his dick and rolled sideways with a soft, lamenting, "Fuck."

A moment later, he collapsed onto his back, arm flung over his eyes.

"Yes," he said, "that was the plan."

The look Christine gave him indicated she believed his statement flippant. But he'd merely applying an alternate usage of "fuck" as a transitive verb. That had been the plan, after all. His body still wanted to execute that plan to completion. Her voice was a sharp note in the quiet.

"Why?"

"Clarify." She groaned in exasperation, but he was not being intentionally obtuse. A lot of questions in that little word.

"Why was this the plan? Why did you want to do this? I mean, I know why I did—"

"Because you are physically attracted to me and saw an opportunity." He turned his head to look at her. "Or so I presumed."

"I'm attracted to a lot of people. It's part of my charm. Also, I was drunk – which believe me, I'm not now. Anyway, that's not my reason. You, however, you had an agenda when you walked into the bar."

"I had no conscious intent I assure you."

"No?"

"I was—I had intended to apologize and confess my reasons for avoiding you. That is all."

"You wouldn't even kiss me."

He had no logical explanation, no reason he resisted that specific intimacy.

If only a black hole were to swallow him up right now…

"Spock," she admonished.

He sat up, tried not to squirm. Squirming was undignified, especially when one was sans clothing. "I find you physically appealing, of course. You are mentally engaging. You have given me useful advice. I…enjoy your company."

"Yes. All very good reasons that were the same yesterday as they were an hour ago."

He dropped his gaze, suddenly and acutely aware she was sitting earnestly before him, cross-legged and naked.

With a small growl, she snatched at a throw blanket before it slid completely over the edge of the bed and wrapped it around her shoulders. After she'd tucked it over her knees and under her toes, there was little to distract him save for the bright nest of her hair and her unrelenting gaze.

"Why, Spock?"

It had not seemed a calculated choice when he made it. It had seemed a spontaneous reaction. He cleared his throat, swallowed the taste of her still in his mouth.

"T'Pring is… weighing her options." He looked up, uncertainly. "Is that the correct use of the expression?"

"If you mean she's looking at alternatives to you, then yes." Her expression softened and he took comfort in her familiar, sympathetic regard. "I'm sorry, Spock. That must be so painful. I know how much you care for her."

He realized Christine had just made assumptions about the state of his relationship with T'Pring. That their engagement had been severed again, though no formal declaration had occurred. But before, when he'd kissed Christine it had been part of a deception. The dissolution of his betrothal a ruse. And he didn't want this to be that.

She plucked at the fabric of the blanket, puffed out a laugh. "So, I guess we're having ourselves some good old-fashioned revenge sex."

"I do not seek revenge." The idea was both illogical and disturbing. Had that truly been his motivation?

She'd used an inclusive plural so perhaps she was speaking about herself. "What vengeance would be served in your case?"

"I found out a team at Daystrom Institute scooped me on some research."

Clearly he'd misinterpreted the nature of revenge sex - which must have been evident in his expression because she burst out laughing.

"Actually, my ex…uh, my former boss wants me back at Stanford. He just got funding for an expedition he's been planning for a few years and has decided I should join him."

"Dr. Korby?'

"Yes. How did you know that?"

"Lt. Kirk heard from an associate that you gave up a fellowship with Dr. Korby and chose the Enterprise instead."

"That's the condensed version."

"Is Dr. Korby's desire to have you join him so egregious as to require… revenge sex?"

"Well, I suspect he's pressuring Starfleet not to renew my contract. He might even convince them to break my current contract early. Also, I'm pretty sure he's the reason my research got scooped."

"Surely there are other qualified candidates who would be grateful for an opportunity to work with him."

"Of course, there are," she cried, pounding a thigh with a balled-up fist. "God, so so many! More qualified than I am. But he hasn't asked any of them to marry him. Four times."

That information went far to expound her well-established avoidance of romantic relationships.

"If he is willing to curtail your options simply for refusing him than you are wise to do so."

"Sadly, it's not that simple. I wish it were that simple. I – I love him. Actually. And I sort of hate him. It's hard to explain."

Not as hard as she imagined. Though, even now, in his anger at T'Pring, he could not conceive a circumstance that would cause him to hate her. Humans used that word too casually. Hate did not run as deep or burn as hot in them he suspected.

"But are we really vengeance kind of people, Spock?"

"We are not." And yet, it was clear now that he'd been seeking justification for a "friends with benefits" scenario ever since Sam Kirk planted the seed weeks ago. All he'd needed was the excuse T'Priung provided to take action. The shame of it was he still wanted to do it.

He looked at Christine, face flushed, her cosmetics smeared, her bright hair tangled and matted. His earlier efforts had painted that portrait. He'd done his due diligence in satisfactory foreplay.

"We – we could, of course, finish what we began, now that our motivations are transparent."

She snorted, eyeing the erection that hadn't diminished much since they'd paused to discuss matters. "Well, some of our motivations are crystal clear, that's for sure."

But any inclination to continue where they'd left off dissolved into awkwardness.

"I know I should reciprocate. That's just hook-up etiquette 101. And ordinarily I'd be all over it, honest. But I kinda think this experiment has run its course for tonight."

He nodded his acceptance and kept his disappointment to himself.

She slipped off the bed and with her back to him, lowered the blanket just enough to wrap it around her torso.

"Thank you for a lovely orgasm. Seriously. T'Pring is crazy to break up with you." She headed towards the bathroom, not looking at him, talking too fast. "And uh, I'm sorry, really, really sorry, I can't – we can't – at least not right now. I need to think. About some stuff. But, please, feel free to go ahead and, um, you know, meditate vigorously while I'm in the shower."

If he did, it wouldn't be on her bed while she was in the shower. He had some dignity left.

He was gone before she got out.

For some reason Spock had yet to ascertain, no matter which lab he used, lab technicians often forgot he was there, sometimes just in the next room with the door open.

He had learned over the years how to tune out the companionable chatter many humans seemed to think enhanced their productivity. His complete absorption in his own work and his usual economy of motion likely accounted for how easily they forgot. This allowed him to indulge his interest in the sociology of gossip and small talk without calling attention to it.

Which is how he learned Sam Kirk no longer subscribed to the "friends with benefits" model of engagement. Because, despite Kirk's assurances to the contrary, a lot of the spouses were not onboard.

"I guess Lt. Henry's husband is stationed at Starbase 12 and somehow caught wind of it. I don't know how Stache's wife found out, but I heard she deep-spaced all his stuff."

"No, she didn't. I've met Aurelan. She's chill. Super sweet."

"The quiet ones are the ones you have to watch."

Which, if either of them had been watching they wouldn't have jumped out of their skins when he appeared next to them at the bench.

"Mind your levels, Ms. Patel," he said, pointing. "This should be at least 2.4 percent above that."

"Yes, sir."

"Yes," she said.

"Yes, what? Wait. Christine? Darling? Are you actually consenting to marry me?"

"I have some conditions."

Roger Korby grinned. "I would expect nothing less."

He loved negotiating with her. Especially since he so often came out on top.

"You have not responded to any of my calls prior to this."

"We have not been in range for direct communication."

"I would have appreciated even a delayed response."

"My duties kept me occupied."

"I wish to resolve our previous disagreement."

"I don't believe we had a disagreement, T'Pring."

"How then would you describe our last conversation?"

"You informed me of your intentions to have sexual intercourse with another man."

"I did not. I informed you of an offer, which I refused, as you would know had you responded to me earlier."

"You – you refused?"

"Healer N'Keth is much older than I and I'm not convinced his wife is as tolerant as he assured me. I had only intended you would be moved to intervene.

To illicit a response of jealousy as he suspected. And now—

"Forgive me. It was childish."

He tried to swallow but his heart was lodged there, a ponderous drum he was starting to feel everywhere.

"You are surrounded by species that are less restrictive in their sexual behaviors," she continued, "and I succumbed to a bias regarding your human proclivities. I am not proud of this. But I have spent much time in meditation recently, reconciling my... trepidation regarding the endurance of our relationship balanced against your exemplary character—"

"T'Pring."

"What's wrong?"

"T'Pring. I have - I have to – I must confess I – I - I may have misjudged, I may have—"

No. No further equivocation.

"I need to tell you something that will cause you pain."