Kozume
Maybe this was karma, but Kei did not know how to manage Kozume. The brat was more attached to Tetsurou than him, and that was totally fine, unless Kozume did everything in his power to try and one up Tsukishima.
Kozume had gotten the power of comebacks from his mother, and Tsukishima wished that he'd kept his snide remarks to himself when Kozume was around. Kuroo, the absolute prick, had only laughed and stated that Tsukishima deserved this fate.
Kozume was a bright kid, with a pretty mop of Tetsurou's black hair and light skin from Kei's side. He picked up on words fairly quickly and used them against his parents at every turn (even if he didn't use it in the right context). Like 'child abuse' when Tsukishima told Kozume that he couldn't have chocolate before lunch. Where did he even hear that from?!
Probably Tooru, a smaller part of his brain supplied in an annoyed manner.
"Mama, I want pocky."
Despite the fact that Tetsurou had hidden his face behind his computer, Kei could almost make an outline of the shit eating grin on his soon to be ex-husband's face.
"It's nearly bedtime, Kozume. You can have pocky tomorrow." He replied smoothly, even though he could tell that he was in for a long night. Kuroo was the one who took care of Kozume the most, being the parent who read up the most on parenting books and having patience with a child, Kozume always came to Tsukishima when he wanted something because 'Daddy is mean and won't give chocolate'.
Which was true. Since Tsukishima was at Volleyball practice most of the time, Kozume was smart enough to pick on the omega when he had the chance. Tetsurou was the stricter parent (which literally no one believed, and Kei couldn't really blame them)
"But mama, I didn't have dessert today." Kozume pointed out, and Kei almost believed him, until he finally spared a glance at his son's face. Nope, there were lies written all over it.
"Lie number 1, sweetheart." Tetsurou replied from his comfortable place on the couch. Kozume was on the ground and playing with his stuffed giraffe while Kei did the dishes (Kuroo and Tsukishima shared the load most of the time, unless Tsukishima had extra practice or Kuroo had to run back to work for a last minute meeting).
Kei had to contain the chuckle which threatened to emerge at Kozume's betrayed look "Treason!" He screeched, pointing an accusing finger at Kuroo, who only blew a kiss in his direction "MAMA!"
"I'm sorry baby but you know the rules." Tsukishima said, with no amount of sorry in his tone of voice, and at Kozume's angry huff, he knew that the tiny omega understood that he wasn't getting his way tonight. But even still, he ended the night with "How about this, if you go brush your teeth and get in bed by the time mama finishes the dishes, I'll let you have chocolate before dinner tomorrow."
When Kozume's face lit up, he knew that he had his son's attention. The three year old ran up to Kei, hugging his leg, thanking him, sticking his tongue out at his dad and tripping over his feet to get to his bedroom. Tetsurou shot Kozume a fond look as he retreated.
"You're such a softie, honey." Kuroo grinned, and at Kei's eye roll, the grin only widened "You know I'm right."
"Shut up Tetsurou, or you're sleeping on the couch." Tsukishima responded, with no real threat, he loved cuddling his husband too much to punish him. At Kuroo's snort, Kei knew that even he didn't believe it.
Maybe he was a softie, or maybe it was just for certain situations. But no matter how much trouble Kozume was now, or continued to be, Kei wouldn't replace the brat for the world.
But maybe he shouldn't fill his son's head with fake promises. Because no way in hell was he letting Kozume eat chocolate before dinner and risk another 'the fall of ipad-chan' incident.