I think I've gotten more sensitive from my time away from BL manga. I can't abide by Kiriya's attitude about cheating.
Kiriya is fine with cheating and breaking up relationships but doesn't want to continue to be with a minor (who he thought was 19 but turned out to be to 17). I just don't get it.
I think how jealous Yuuya would get is a problem. It's a common theme in BL manga and it's almost treated like it's a positive thing, a sign of the seme's love. I think that's so problematic - look what jealousy and greed has made people do. Does murder ring a bell? I think before any relationship goes too far, the jealousy should be addressed. I understand that Yuuya is young, but he's the one trying to be in a relationship with a 27-year-old so he needs to learn to deal with these feelings instead of letting them control him.
"I just want to run off with him." - Yuuya
If you had a secure job and friends, wouldn't that scare you if your lover started saying things like that, along with the jealousy issues?
I did think the piano part was interesting, it's not often a character has a permanent disability. I also thought it was unusual in a BL manga for a teacher/student relationship to get caught, so that was new. Yuuya didn't even apologize for making Kiriya lose his job though, one which he clearly enjoyed. He didn't care that his fellow students were getting a better education because of him and would now lose that. He just wanted Kiriya to himself.
I did find myself enjoying it a bit more after they were caught and had to find a way to see each other again.
I just hope that in time, they'll both grow as people more together and apart, and their relationship will strengthen.