PREACHHH SAME !!!
I believe it's alright if the characters don't mind being called mommy and daddy. In the end, it's what the children want. If they want a mom figure in their lives, they can choose whoever they want as their mom. After all, in the manga, the kid is surrounded by other kids whose parents are "mom" and "dad." The impression of needing a mom role was there to begin with.
Yes, I do understand this, but it's not simply "the child decided it", it's more like "the always dominant seme proposes it to children". Besides, in this specific manga it'd make more sense if the child called the uke to be his dad, 'cause that's how it "works" in a heteronormativity world. I don't know, it just sounds so sexist to me..

I REALLY DO HATE THIS "DADDY AND MAMA" THING IN YAOI MANGA!!! For fuck's sake, they're a gay couple, they'll be Dad and Daddy or something similar. There's no feminine figure uuuuuuhhhh