you left the most likely at the end i suppose :D these sorts of mangas usually goes like that i suppose :/ or 5, 6, 7 if not the 2.
amen sister ! or bro ...
nope ı think high school kid will be the sandwich between the old man and teacher ımean title and cover basically tell us this ofc this my opinion ╮(￣▽￣)╭
ummm do you want spoiler?
hahaha
Ways this can go:
1) Threesome with either them eventually parting ways or staying together
2) Father and student start a relationship over the common unrequited love interest
3) Son cheats on wife with father bittersweet end
4) Son cheats on wife with student with bittersweet end
5) Son toggles back and forth between father and student before either ultimately choosing one of them
6) Son toggles back and forth between father and son before ultimately choosing wife
7) Son stays faithful and the wife is actually the cheater and he takes comfort in the other two