Tobio-chan
Tooru groaned when the shrill cry of an annoyed baby rang through the peaceful night of the Iwaizumi household. Hajime, the absolute prick that he was, groggily stretched out his hand to paw at his phone and look at the time. Tooru let out a yawn, getting up from his comfortable place in his darling Iwa-chan's arms and looked over at the crib in which his 3 month old was screaming his lungs out.
"Tobio-chan." Oikawa cooed, gently heaving up the grumpy alpha into his arms. Tobio calmed down a little, loud wails reducing to occasionally sobs and sniffles "Are you hungry?" He looked back at Hajime, who was fully alert now and awake. Maybe it was his dumb alpha instincts to protect his pup and mate, or he just didn't want to go back to bed and leave Oikawa alone to take care of Tobio. Probably the latter.
Tooru never slept with a shirt on anymore. One, because Tobio was one of the most demanding babies he'd ever seen, and two because his nipples were sore 24/7 because of said demands. When Hajime and him were younger, Tooru sleeping without a shirt usually meant fun sexy times. Now it was just because they had a hungry baby constantly crying for milk.
Volleyball had taken kindly to him, which was incredible as being an omega and accomplishing so much was still hard in this time and age. Iwaizumi had, surprisngly, started studying to become a doctor (a surgeon to be exact, it was gross, but the man was known for his strong stomach). In the beginning their lives had been hard to balance, with their work schedules and Oikawa's knee occasionally acting up, but they made it through. Three years later, their little miracle boy showed up and everything just became better. Their parents, despite Hajime's excessive warnings, spoiled Tobio rotten (Bokuto and Kuroo weren't any better in the sense, since Tobio was the youngest baby they had in their pack)
Tobio also had a weird attachment to volleyballs, constantly pushing them around and sinking his gums into them as a teething mechanism. Tooru often commented that Tobio was nothing but an untamed dog, to which Hajime smacked his head hard enough to see stars. That, and Hajime was a very protective father.
Tooru slithered into bed with the sniffling baby, pressed against Hajime who ran a hand through his (already) messy hair "He's not hungry." Tooru complained when he brought Tobio up to his chest, the baby didn't even stir, just happy to be nuzzled between his mother and father.
"He just wanted your motherly love, Oi." Iwaizumi yawned weakly, even as Tooru gently pinched his thigh. Hajime never stopped calling him Oi, for one, or any of his mean nicknames from back in the day. Tooru was for special occasions (wink wonk) or an accidental slip of tongue. The alpha's finger poked Tobio's chubby cheek, gaining a glare from the 3 month old baby "Sorry Tobio, your mommy was mine before he was yours."
Tobio was more of a mommy's boy than he was a daddy's boy. He liked being with Oikawa more, since the omega was mostly busy at Volleyball practice (once a week, since Tooru was still on maternity leave and didn't want to skip) so Iwaizumi had more time to spend with Tobio. Which channeled into this 'I want mommy' phase and Hajime couldn't help but feel a little hurt about it. Then again, Tobio still loves playing aeroplane with him, so that's one thing he'll always have with the grumpy baby.
Hajime and Tooru watched Tobio's eyes droop, the scent of his parents slowly lulling him back to sleep. Tooru placed a small kiss upon his baby's head, and winced when his nipples brushed against the soft mattress underneath.
"I told you we should've got the breast pumps."
"I told you that, Tooru. You didn't listen."
"Yeah well I'm stealing your idea and blaming you."
"You're going to wake up Tobio, go to sleep."
"No yOu." Oikawa said peutantly, placing the sleeping babe between himself and Iwaizumi as they got comfortable again. Hajime chose not to respond, instead just playing with the short mop that was Tobio's hair and closing his eyes "Wait I didn't actually expect you to sleep." He said, incredulously, and maybe the "Iwa-chan!" was far too loud, because Tobio was awake again and wailing at the top of his lungs.
Tooru can't necessarily say he didn't deserve the hard smack on the head from his husband.