It might be a shounen-ai actually I don't remember them having sex. It's basically two high school guy friends where one walka in on his friend mastuerbating and then becomes intranced with that guys ass.
Possibly this? http://www.mangago.me/read-manga/toshigoro_no_otokonoko_to_are/
It might be a shounen-ai actually I don't remember them having sex. It's basically two high school guy friends where one walka in on his friend mastuerbating and then becomes intranced with that guys ass.