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Karamatsu was so pretty like this, full and round with Osomatsu’s children. The doctor had said there were eight babies this time, and oh did he look like it even early in his pregnancy. Before his scent even hinted at it and before Karamatsu knew that he was pregnant his stomach was rounding out.
God, when Karamatsu had reached for something on the bookshelf and his hoodie had ridden up, showing off his then small bump to Osomatsu by accident, he’d gone nearly feral.
That was His Omega. His pretty Omega brother was pregnant with His children. It didn’t matter that he had no right to fuck a breeder as a shit tier Alpha. Karamatsu had spread his legs for him anyways, gone into heat just for him, gotten knocked up just for him. Not that he had much of a choice with how much cum Osomatsu had poured into him over and over and over.
The way he sat there with all of them now, absentmindedly holding and caressing his ever growing belly was driving Osomatsu crazy. None of his tops fit him properly anymore, so Osomatsu’s hard work was on display for everyone to see. Karamatsu’s scent was so rich now too, everyone could smell how fertile and pregnant he was. If only Osomatsu was allowed to mate him properly, then he’d smell like the father of his children too.
Recently though, he’d finally been developing breasts. And oh, were they so soft and tender and filled almost to bursting with milk. He was always leaking, his nipples red and raw and erect. Maybe it was because he was a breeder, but his tits were huge now. They felt so good when Karamatsu gave him titjobs. It felt extra good because Osomatsu was the cause of them.
He had gained weight too. His bony frame was nice and soft now. Fat settling nicely on his hips and his ass.
He was perfect. And Osomatsu had done this to him.
Spearing Karamatsu on his cock multiple times a day because Karamatsu had become so cock hungry and horny the deeper he got into his pregnancy was also a bonus. Half the time Karamatsu wasn’t even a person anymore, but a complete brainless breeding Omega like he was meant to be. It was so hot seeing him turn into one, seeing how happy and grateful he was when Osomatsu painted his insides white for the fifth time that day. He wondered if Karamatsu would stay like that once he gave birth.
Osomatsu wanted to fuck him fast and hard like he used too, but Karamatsu couldn’t take it anymore. So their sex was slow, grinding his dick deep into Karamatsu’s snug little pussy, right against his cervix. Karamatsu always made these little sounds, breathy gasps and hiccups that he never did before the pregnancy that had made Osomatsu bust a few times without meaning too.
His pussy wasn’t tight anymore, and it was so shallow Osomatsu couldn’t fit the knotted part of dick inside anymore. It turned him on, knowing that Karamatsu’s body was getting ready to give birth to his children.
His children.
He had never cared about anything besides himself and sex before he knocked up Karamatsu. And here he was, obsessing over his brother and the eight babies he’d knocked him up with. It had to have been an Alpha Thing. Why else would he be so territorial and over-protective of Karamatsu now? He could barely keep himself from mauling Ichimatsu if he was in the room with Karamatsu.
If he really thought about it, how sick Karamatsu had been at the beginning of his pregnancy scared him. A lot. Seeing him now, laughing and talking energetically with everyone with a hand lovingly placed on his bump was a far cry from how he had been. Karamatsu was enduring all of it for Osomatsu’s sake.
As the afternoon wore on, Karamatsu’s eyes kept glazing over, turning glassy before returning to normal. He was trying his best to stop himself from going into his Omega head space, but the Omega side was slowly winning. Karamatsu’s innate need to please everyone, especially his Alpha fed so easily into his breeding Omega nature. Osomatsu wanted to fuck him right now, in front of everyone. Show off his Omega’s pretty new figure and sopping wet pussy to the rest of his brothers.
“I’m going to lie down,” Karamatsu said. “Will you help me up, Alpha?”
He was so cute when he talked like that, calling Osomatsu ‘Alpha’ instead of his name. Omegas usually only did that when they were in heat, but Karamatsu did it a lot now in casual conversation. He probably didn’t even realize he was doing it, and Osomatsu didn’t want him to stop.
“Yeah,” Osomatsu said, getting up. He pulled Karamatsu upright with some difficulty, he wasn’t exactly well-balanced in his current state.
“Thank you, Alpha,” Karamatsu said, flashing Osomatsu a lovely little smile. Too bad he could feel Ichimatsu seething from where they stood. It filled Osomatsu with a sense of pride that he’d claimed Karamatsu first. Ichimatsu would never be his first, and even if he bred Karamatsu after this pregnancy he’d always be second to Osomatsu. How awful.
“Lemme go with you,” Osomatsu said, and Karamatsu nodded his head in response.
Karamatsu sunk into his Omega headspace not long after the two of them had laid out their futon on the floor. He was exhausted, and opted to lie down instead of servicing Osomatsu’s cock like he normally would. Osomatsu could live without a blowjob today, he could worship his Omega instead.
Osomatsu laid next to him on his side, snuggled in so close his breath made the skin on Karamatsu’s neck prickle. His hand joined Karamatsu’s on his belly, running it over the expanse of it. Karamatsu sighed contently. He was purring.
“My sexy pregnant Omega,” Osomatsu said, licking a strip along Karamatsu’s elegant neck.
“Alpha...” Karamatsu groaned. “Alpha did this to me.”
“I did,” Osomatsu said. “I made sure to breed my Omega good and full.”
“I’m so happy you did.”
“Good.”
Their conversations never really went any deeper than that, not that Karamatsu could hold one in his current mind state. Everything important had already been taken care of or talked about now anyways. Osomatsu already knew their parents were furious at him, knew that he would have been disowned and thrown out had Karamatsu not begged on his knees for him to stay. His children were going to be adopted out to four different Beta families and the money they’d get in return would help the entire family. Karamatsu was ok now. They were ok now.
Karamatsu was still purring against him, his eyes closing as he drifted off to sleep.