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Mycroft fought with consciousness, content to stay in his cozy dream world for as long as the waking world could spare him. The vision behind his eyes was more of a fantasy--an unspoken desire he could never have in the light of day. His fingers were idly stroking his cock under the covers as the omega in his mind rode him almost maddeningly slowly. Each time those hips bore down against him, they twisted, drawing him deeper into that imaginative heat. His senses were full of the dream's desire--the overpowering slick of those depths, the scent of an omega, one that had been haunting him for days.
His clothed cock surged upwards into his fist. The dry cloth of his pants and pajamas was nothing compared to the wet warmth of the anonymous man behind his eyes. The friction was building to a crescendo, both in his fantasy and under his practiced fingers, but before Mycroft could finish, the spell was broken. A stifled groan sounded everywhere except inside Mycroft's imagination, bringing him into reality with a force that would’ve caused whiplash if his head hadn’t already been pressed back against his pillows. His eyes snapped open, wandering.
Across the room, Sherlock was curled in one of the chairs, knees tucked under his chin, eyes focused on Mycroft's erection.
Mycroft covered himself with the down comforter he had been trying to kick away only a moment prior.
"Sherlock--" He wasn't sure what to say to the pale young man tucked away in the shadows. What he was sure of was that the scent of an omega since he’d returned home hadn't been a figment of his imagination. The realization dawned on him painfully slowly--the phantom scent he'd been tracing for days had been his own brother, an apparently late-blooming omega the family had always assumed to be the odd beta in the tree. And now here he was, nineteen years old, having his first heat and watching Mycroft have a wet dream.
"I can't think," Sherlock grumbled against his kneecaps. "I haven't been able to think all night. There are things--things I need to do that I can't because I can't bloody think." Sherlock unfolded his long legs out in front of him and Mycroft tried to hold his breath against the stream of pheromones the motion created. It was useless--the smell of Sherlock's fresh sex hit him like a train and he fisted his hands in the bedclothes to keep from ejecting himself from the bed and pouncing his younger brother.
This was all wrong--there was a reason omegas in heat were locked away like virginal princesses in towers.
Oh God, Mycroft thought as his brother moved toward the bed, he's never had anyone. No alpha has ever touched him, not even smelled him.
The hard length resting against his navel twitched, making its intentions to be the first completely clear.
Mycroft, for his part, knew he needed to send his brother away. The younger man's hormones were going crazy. The desire he was feeling--they were both feeling--wouldn’t be there without the jumble of hormones in the air to urge them on. No matter what they may have been feeling in the heat of the moment, it didn't make it right for the elder Holmes to take advantage of the situation; of his brother.
The thick scent hung in the air between them, and Mycroft's eyes rolled back behind closed lids when it intensified. He didn't need to look--or even listen--to know that his brother had shed his pyjamas.
A breath later, a set of long, slender fingers dexterously slipped the button through the hole on Mycroft’s pajama bottoms, immediately reaching inside and fishing out the leaking prize within. Mycroft kept telling himself he'd stop it--they'd both come to their senses any moment. They were each brilliant in their own ways; their minds would overpower nature sooner than later.
But then Sherlock was climbing onto the bed and Mycroft didn't know how to fight it. Truth be told, aside from the niggling voice in the back of his mind, he didn’t want to fight it. Alphas weren't trained to fend off advances the way omegas were; there was no self defense to warn off potential partners. There was no need. Alphas had the desire to mate and breed in the very core of their DNA. Why would they fight when that need was offered satiation?
"Sherlock--" Mycroft tried, but the words caught in the back of his throat as his brother flicked his thumb over the glans of his penis before running the thick fluid down to the base. He gave a twist of his hand before coming back up and repeating the motion until Mycroft's cock was lubricated with his own excitement.
Mycroft knew it was unnecessary. He could smell Sherlock's readiness without needing to touch; he knew the unfamiliar, hot opening was slick and ready for him, whether he was an absolutely willing participant or not.
"I just want to think again," Sherlock mumbled as he straddled Mycroft's hips. "Need you... to help me think again."
There was something in the way Sherlock's eyes burned that made Mycroft want to keep him like that forever. He wanted to watch those eyes flutter closed in ecstasy; wanted to see how far back Sherlock's neck would bend as his body arched and begged for more.
Unfortunately, he missed both of those things happening only seconds later when Sherlock slid himself down on Mycroft's cock. He missed the surprised, satisfied moan that slipped from the younger man's throat because of the shamed and blissed groan that tore from his own when the head of his cock slipped all the way into that waiting warmth.
"Oh yes," Sherlock hissed, throwing his head back and moving up and down in shallow bursts. "Yes, that's exactly it. Yes. Oh." His mouth opened in the dim lighting and formed a perfect heart, freezing with his head thrown back for a long moment. Mycroft knew pornography would never have any appeal to him ever again.
In school, once he had presented as an alpha (one of many in his family, a proud trait) they had taught of heats as an omega's fire that could only be extinguished by a superior; an alpha who would come along and grant them a reprieve from the desperate need to couple that was bred into their biology. So he had always believed that he would be doing a favor to an omega if he ever had the chance at one. It came to be, of course, that now that he had an omega in his grasp--sliding up and down on his cock with wanton hip wiggles was surely as close as one was likely to be--he realized it was quite the opposite.
His primal instincts told him that he had been chosen for this--this omega (blood was no matter to his instincts) had picked him for a task; was trusting him to satisfy.
And even though the part of him that knew this incestuous bond was wrong still pecked away at him in the back of his mind, Mycroft fought it; it was simple biology that their reproductive cells would cancel each other out to avoid impregnation. Knowing this, his body responded near equally in both directions. Sherlock's shallow thrusts (his body seemed reluctant to let Mycroft too far out for fear that it would not return) prompted him to pump upwards in search of deeper penetration, though his mind was telling him to retreat. Similarly, his hands were gripping Sherlock's waist and trying to pull him down and impale him on his cock anytime he moved away.
He actively knew he should have been pushing him away. Instead, he was encouraging it with every tremble of muscle, with every pulse of his cock as he sped closer and closer to climax.
"God, Mycroft," Sherlock gasped. He was very nearly panting now, chest rising and falling, pale skin flushed with arousal and need. His dark curls fell forward into his eyes when he leaned forward for a different angle. "That's it, just there. Oh, oh, yes, that's right. Fucking--yes. Yes."
Sherlock's movements sped up, though they remained just as shallow. It was no matter to Mycroft. His cock was being worked by Sherlock's most intimate walls. The head of his cock was receiving special attention from the deepest parts of him each time a few inches slid in and out of his brother's virgin body. The exquisite pull was almost greedy, and Mycroft was determined to give whatever was expected of him. He was an alpha; it was his gift to give.
"Oh, God, I can feel it. It’s--oh," Sherlock gasped. He nearly doubled over as the base of Mycroft's cock began to swell inside him, the knot pressing insistently and joining them further. It became nearly impossible for either of them to move, and on instinct, Mycroft grabbed his brother's slim hips harshly and pulled him, effectively seating him all the way down.
No sooner was Mycroft buried to the hilt, Sherlock's head fell back in a silent scream as the cock deep inside him tensed and pulsed. Under his thumbs, the alpha could feel the tense muscles of Sherlock's abdomen as their orgasms ripped through them simultaneously. A small stream of white fluid was pooling by Mycroft's belly button, but it was noting compared to the still-pulsing member buried in the omega's moist hole.
It was barely another breath before Sherlock curled forward and collapsed onto Mycroft's chest, barely gentle with their joined bodies.
"Thank you," Sherlock whispered against his neck. He sounded sated, more peaceful than Mycroft could ever remember.
The alpha wanted to tell him that it wasn't over yet; that if he knew anything about heats, his brother would be uncomfortable and in need of another good go before dawn. Instead, he tentatively settled for stroking back his little brother's curly, sweat-damp hair.
Their connection was still just as strong several minutes later, and while Mycroft was thankful his brother hadn't yet gotten restless, he was losing feeling in his left thigh. He intended to simply widen his legs so he could better support Sherlock's weight on his hips, but when he moved, their bodies slotted together just a bit more. Suddenly, the room was filled with the scent of Sherlock's pheromones for a second time, as if his brother's slight movement had been a trigger.
That was all it took for Mycroft's body to respond, for his cock to stiffen inside Sherlock's body, where it had just been beginning to settle. Mycroft supposed it was because they were young; especially so since Sherlock was still in his teens. Either way, the knot had settled almost instantly in order to give his cock the space to move through a second session.
"Yes," Sherlock whispered in his ear as Mycroft’s cock stirred inside. Like everything else, it was a new sensation for the both of them, and they took a long moment to savor the excitement of Sherlock being stretched from the inside by the hard length of Mycroft’s cock. "I'm ready. Again. Move."
Before, Mycroft could have been labeled a somewhat passive observer. He hadn't wanted to move; he had tried not to give in to his brother's (or his own) urges. He’d failed. Now, if he was going to hell--he figured he may as well enjoy the ride.
And he did. God, he did.
It was eight minutes later, when Sherlock's legs were hooked around his waist and his heels were digging into the small of his brother’s back with their efforts to draw him in deeper--that was when Mycroft stopped caring about decency. Why it had taken him 47 minutes to get there was beyond him, but now that he had thrown away the map, he was glad of it.
His cock slid in and out of his omega with an obscene, slick sound that sent shivers through him every time the volume of their passion increased. The first round had been made up of short, almost abortive thrusts that had been satisfying for a one-off. Now that he was in control, Mycroft's needs were being met with long, slow thrusts that filled that warm hole before sliding almost all the way out and then pressing back in with urgency. The positions were reversed, but it was almost like the dream Sherlock had woken him from--only now, he wasn't going to finish in dry fingers; he was going to reach his finish inside of a hot body that would envelop him and draw it out.
Sherlock's teeth were nipping at his bottom lip. They had yet to claim each other's mouths, and Mycroft found himself wondering what his brother would taste like in the moments before climax. Kissing seemed almost a technicality at this point, and when Mycroft felt the tension of release building in his stomach, he leaned forward with lips parted in a groan, letting his brother swallow it whole.
"Harder, Mycroft," Sherlock gasped against his lips a moment later. His teeth grazed his brother's jawline and he wheezed the word again: "Harder."
The larger man obliged for half a dozen thrusts, until Sherlock's body sucked him in and clamped down around him so unrelentingly, the only option was bury himself as deeply as that lithe body would allow, let go, and enjoy the engulfing heat that welcomed him so.
It would all be different in the morning--or maybe it would be the same, but with a new understanding added to the animosity between them and a new level of protectiveness on the part of the elder. But it didn't matter. They'd always be Mycroft and Sherlock Holmes, two siblings who couldn't be more contrary. They wouldn't fool themselves into thinking it was something different.
But now they shared something that they could only truly give each other. That was what would make the morning's potential awkwardness bearable. Mycroft knew--knew with almost exact certainty--that Sherlock would never seek this kind of relief for his plight in arms other than his own.
That in mind, Mycroft settled himself over his brother, occasionally twitching in unexpected pleasure when their joined bodies worked together to milk him further. He rested his head on Sherlock's shoulder and waited for the other man's breathing to calm before closing his eyes.
Yes, there would certainly never be another, not for either of them.
Mycroft was content with this knowledge, even when he'd not considered such an arrangement before.
When their bodies relaxed and they were released from their bond, Sherlock rolled them over. He expected his brother to leave, but when the younger man rested his head on his brother's shoulder and pulled the blankets around them, Mycroft realized that Sherlock was accepting this new development just the same.