I'm more concerned about the love here. To me it looks like the seme was not only affected...

I'm more concerned about the love here. To me it looks like the seme was not only affected by the thought of "a normal family with children" but he had also run out of feelings for the uke. When they reached 28, the way he treats their relationship shows no emotion at all, like he's just going with the flow, and he's bored of it, and as a result, he's easily convinced when the idea of "normality" hit him.

I'd like to see how the manga describes his feelings toward his lover more when he told him to break up, but it's only about his actions.

I've read some mangas about ones breaking up with their lover with reasons like "no future", too. In "Doushitemo Furetakunai" and "Kowagaranai de, Soba ni Ite", the ukes also wanted to break up thinking their semes deserve "a normal family with children" after seeing their semes talking about family, so those ukes thought that they should give up. However, those mangas described how painful they felt when they came to that decision, and their reluctance as well, since they still loved their partners so much. But with this manga, all I see are the seme's coldness and unreluctant actions.

But well, of course he'll regret like it's always been in yaoi, and they'll come back to each other, haiz. I hope it'll be poignant and beautiful as people that has read the raws said.