Responses
http://www.mangago.me/read-manga/tsuyogari/ (2nd story)
http://www.mangago.me/read-manga/the_last_lover/ (well he kinda regretted it after a while for like a bit, kinda a messed up one though)
A yaoi manga where the seme regretted having sex with the uke the first time but came to realized he like him at the end ?