Leonard had always been try-sexual. (“I’ll try anything twice,” he’d said one afternoon on the couch, with his head in Jim’s lap. He’d been lulled into a pleasant state of semi-consciousness by Jim’s fingers massaging his scalp.) However, there was one thing he’d been perfectly adamant that he didn’t want from his sexual relationship with Jim: he was all for sex, but he has never enjoyed being fucked and does not want to be penetrated. Period.
The closest Jim had ever gotten was during a blow job, when he’d taken over stroking Leonard’s spit-slick cock with his hand in order to suck at his balls. He told himself it was an accident, sliding his tongue lower, past Leonard’s perineum to tongue at the edge of that wonderful bundle of nerves. Leonard had never come harder; he’d also made sure from that point forward that Jim’s mouth stayed away from that area, much to his dismay.
Jim was okay with this primarily because Leonard happened to have some kind of sixth sense about how to reduce Jim to a mess of nerves and come.
The thing is, Jim knew he could get Bones to like it. He just needed a chance.
So for two weeks, he practiced three dimensional chess with Spock. At the end of the second week, getting the Vulcan to admit defeat was like pulling teeth; Jim’s victory was guaranteed with the knowledge that he could beat a Vulcan at a game of logic.
The following afternoon, Jim challenged Leonard to a match. And let him win, of course; Jim Kirk is a master at sharking, has been since he was old enough to understand a lie. It was only a white lie, Jim told himself. When he lost, he made a show of huffing and puffing and challenging Leonard to a rematch, this time with an added stake: loser gets to do whatever they want in bed, with ground rules:
1. There will be a safe word, just in case.
2. The other person can back out of any scene at any time using that safe word, and they’ll resume the game the next night.
3. The game is primarily for the bedroom; however if, at any point, the winner wants to cash in outside the bedroom, the loser has the right to say no.
There were other rules, but they were all basically the same: the loser to the winner. The winner had thirty nights.
Leonard agreed instantly. He lost colorfully. His glare was murderous when he leveled it at Jim. “You played me.”
"A little. Are you backing out?"
It took him a long moment of inarticulate grumbling, but Leonard finally said that no, a bet was a bet. “I’ll try anything twice,” he growled, albeit begrudgingly.
The first three nights, Jim didn’t do much of anything out of the ordinary. He positioned Leonard on his hands and knees, legs spread just slightly, and jerked him off that way. All three nights, he let Leonard come onto a towel laid out beneath him.
"Not much need for a safeword, kid," Leonard said on the third night, after Jim had fit himself into Leonard’s arms for the night. Jim feigned sleep, smiling in the dark.
On the fourth night, he kept his hand stroking over Leonard’s cock. He’d taken to kneeling beside him and rubbing his hand up his back, over his shoulders. As Leonard was nearing orgasm, Jim backed off.
"Remember the safe word? Don’t say it, just say yes or no."
Leonard turned his head and bit out, “Yes!”
Jim nodded and leaned over, sinking his teeth into the ass cheek closest to him. He soothed over it with his tongue, listening as Leonard howled and jerked into Jim’s hand, coming hard and sticky through his fingers. Jim licked at his hand while Leonard rolled to his side, attempting to glare at Jim.
The next night, he repeated his question, right as Leonard neared the edge of orgasm, and he nodded fitfully, his head hanging down from his shoulders. Jim spread his cheeks apart, exposing his hole, and let breaths of warm, damp air puff over it. He watched Leonard pucker and clench through his orgasm, groaning tightly.
On the fifth night, Jim didn’t bother asking. He spread Leonard’s cheeks - waited a few seconds for his safeword - and upon hearing nothing, pressed his tongue into the cleft. Leonard’s body jostled as he dropped to his elbows, a tortured moan escaping his lips; no word, not even a “stop” left his lips.
Jim flattened his tongue and worked over it slowly, exploring the sensitive skin on the outside. He never stopped stroking Leonard, but had moved to this part of the game when Leonard was minutes from orgasm. He still came sooner than he had all week.
The next three nights went the same; each time, Leonard fell to his elbows, unable to hold himself up on his hands, and Jim ground his dick against the bed while he licked and sucked at the sensitive skin around Leonard’s ass.
Jim never teased him about liking it. Leonard never said he didn’t, nor asked him to stop.
On the ninth night, Jim got him close, then stopped stroking. It was purely unintentional, taking a cheek in each hand and pulling them apart obscenely. Leonard was barely holding himself up on his elbows and when Jim buried his tongue in his ass, Leonard let out a shout and dropped face-first into the mattress. Jim tongued enthusiastically, probing past the pucker that had gotten looser as Jim worked his tongue over it that night.
He remembered after a minute of vigorous tongue-fucking to wrap his hand around Leonard’s dick; three pulls and Leonard let out a high-pitched whine, spending himself in Jim’s hand.
Jim had to roll him over and Leonard’s cheeks were tinted red the entire time Jim cleaned up; he quietly re-brushed his teeth and gargled mouthwash before getting back into bed. Leonard was facing away from him, so Jim spooned up behind him, mouthing his words into Leonard’s shoulder.
”Thank you for trusting me, thank you for letting me.”
Leonard didn’t reply. Jim didn’t ask him to.
On the tenth night, Jim was already behind them when they started. When Jim used one hand to part his cheeks, licking once up the length of the cleft, Leonard tilted his head back.
"Fuck," he hissed, arms trembling. Jim kept his movements slow, both his tongue and his hand around Leonard’s cock. He waited until Leonard was up in his head before slicking up his skinniest finger with lube; when he was lose and pliant, dropped onto his elbows, Jim delicately pressed the first knuckle into him. He left it there, kissing Leonard’s cheek, tightening his grip on Leonard’s dick in an attempt to keep him from using the safeword.
He didn’t say it. Instead, he fisted his hands in the sheets and rested his forehead on his arms, panting heavily. Jim pushed in gradually, up to the second knuckle. Leonard came a few minutes later, and Jim felt him clench around the digit.
The next night, Leonard used the safe word the moment Jim spread his cheeks. Jim stopped entirely; instead of having sex, Jim curled up at Leonard’s side, laid his head on Leonard’s chest, and asked Leonard to read to him.
His not-quite-boyfriend obliged, and Jim stroked his hands up and down Leonard’s chest as he read aloud, occasionally pausing when Jim brushed past his nipples, occasionally letting out a soft moan when Jim squeezed his fingers around a patch of hair and pulled gently.
Leonard got hard at times, but Jim ignored it the rest of the night.
The next night, Jim didn’t even bother with the routine they’d established. He ordered Chinese takeout and they spent the night on the couch, in sweats, watching Abbott and Costello. After they ate, Jim crawled into Leonard’s lap, kissed him breathless. Jim pushed their sweats down enough for him to sink onto Leonard’s cock, and Leonard fucked up into him, moaning into Jim’s shoulder as he came.
On the thirteenth night, Jim once again ordered Leonard to his hands and knees on the bed. He used his tongue to loosen him up and get him close. He slicked up his finger. He pressed it in as far as it would go and wriggled it side to side until he found it, found the little nub.
Leonard dropped from his hands to his face, a dry sob of pleasure wrenched from his throat. Jim stayed still, simply pressing against the little nub, his hand still stroking. Leonard came with a violent shudder and Jim’s name moaned past his lips.
The next two nights went the same.
On the sixteenth night, Jim used two fingers; he scissored them back and forth and even moved them in and out, making sure they passed Leonard’s prostate over and over and when he came, Leonard cried out Jim’s name like it was a curse.
In hindsight, it probably was.
Three nights later, Jim was still using two fingers, rubbing lightly at his prostate, when Leonard sobbed out, “More, please more, more Jim.”
Jim was so caught off guard he lost his rhythm, but he added a third digit and when Leonard came, it was with a shout and he pressed his hips back hard against Jim’s hand.
On the twenty first night, Leonard started out face down on the mattress, anticipating that he’d wind up there anyway. Jim worked him up slowly, starting with his tongue as it had been a few days. He pumped his fingers in and out slowly, his other hand alternating between Leonard’s cock and his back. He came with the steady sweep of Jim’s fingers over his prostate, thrusting into empty air.
The next night, Jim hardly touched his cock at all. He held him open and tongued him loose, gave his cock a squeeze, and started stretching him with his fingers. It went easier every night, but Jim never sped up his routine.
Leonard came quickly that night, after Jim remembered to stroke his cock again.
The night after that, Leonard came without Jim touching his cock once.
Three nights later, on the twenty sixth night, Leonard sobbed through his orgasm, thrusting back onto Jim’s fingers.
On night twenty seven, Jim had a fever. On twenty eight, he was still weak from it. On twenty nine, they accidentally fell asleep on the couch at 8.
On the last night of their agreement, Leonard asked Jim to fuck him.
He was already at two fingers and pushing back against Jim, his cock flushed in Jim’s other hand when he asked.
"Are you sure?" Jim asked, kissing his hip. "I’m happy with this." He swept his fingers firmly over Leonard’s prostate, drawing a high moan.
“Yes, Jim, please just fuck me. Fuck me.”
"Okay, easy," Jim soothed, pulling his fingers out. Leonard whimpered at the loss and Jim guided him over onto his back, with a pillow under his hips. Jim rolled a condom on and slicked himself up, then returned his fingers to his hole. Leonard’s chest was flushed and his eyes were fixed on the ceiling. Jim kissed the inside of his knee and moved into position once Leonard was taking three fingers with ease.
"Remember the safeword?" Jim asked, and Leonard nodded curtly. His legs were spread wide for Jim’s hips.
Carefully, Jim started pressing into him. The head popped in after a few long seconds, and Leonard bit down on his bottom lip. “Bear down on me,” Jim grunted, holding tightly to one of Leonard’s thighs. The pressure on his head eased and Jim took in a deep breath, looking down at him. “How you doin’?” Jim asked, reaching for one of Leonard’s hands.
"Okay. Just move, Christ, move."
Jim gritted his teeth and inched forward, playing close attention to the stress on Leonard’s face.
When it eased, Jim started a slow rhythm, adding more lube to ease the grip of Leonard’s ass around his girth. He reached down and started stroking his cock, which had lost a bit of hardness at the beginning, but was starting to harden again. Jim adjusted his angle and when he hit the mark, Leonard threw his head back and moaned.
Jim leaned over him, braced on his arms, and greedily swallowed the sounds he was making.
Before too long, Leonard was digging his heels into the small of Jim’s back, all but sucking him in on each thrust. Leonard came with a whimper and without warning, clenching around Jim as he pushed all the way back in.
Jim stopped moving and shuddered, both of their orgasms creating seismic waves that seemed to make every pulse of their cocks that much more torturous.
Sweaty and breathing heavily into his shoulder, Jim returned to himself. He kissed Leonard’s collarbone sloppily, wetly, and pushed himself up to look down at him.
Leonard had nowhere to hide, not this close, but Jim pressed their foreheads together and closed his eyes.
"I love you, Bones. You have no idea…"
"I love you too, kid," Leonard whispered, clutching Jim closer.
After that, he didn’t have much of a problem with Jim putting things up his ass anymore.
He balked when Jim suggested he wear a plug when they went grocery shopping; it didn’t take a lot of convincing, though.