I agree but I also think what uke did was valid in his POV as well bcz of the fact that they didn't talk it out and according to what's said later, while uke is gay the seme seems bisexual (leading to internal insecurities and homophobia ) and it's pretty common to let go of your loved one to prioritize their happiness.
He was def not mad at ml liking his nephew, being born or being friendly with kids. He was more mad that he couldn’t provide that future for ML. That’s why he wanted to break it off, and there was just a lot of anger that was coming out because he lived in a household where they would not accept him for being gay and for not being a social norm nuclear household.
This is a goddamn story about internalized homophobia and being upset with yourself that you couldn't provide them with the family and children that your partner wants
"There was nothing to be confused about" YOU're the one that's confused XD
You weren't supposed to take "the kid bumping into him" literally.
That kid was there to signify that the ml cares for children a lot, and a reminder to the mc can't give the ml his own kids to care for. It's not easy for same sex couples to adopt and get married in japan.

It kinda put me off when the uke ditched the seme for liking kids