can anyone recommend me FLUFF bl school love story that has smut after they turn into adul...

100% this one:
https://www.mangago.me/read-manga/sun_kissed_heartbeats/

This one has a bit of angst but they're relationship is so sweet:
https://www.mangago.me/read-manga/spinach_bouquet/

This one is also like what you want but its more comedy
https://www.mangago.me/read-manga/can_t_help_it/

Spinach bouquet

already read that sorryy

THANKSS