I've been searching a long time and can't remember the title of this manga. The story about two male that have each other girl friends but the fall in love then. The seme have girl friend but haven't end up yet. The seme love uke and also don't know to do anything with his girlfriend. The uke for being jealous but he loved him so much and decided broke up with him by raped that girl. Actually he still loved and remembered and the seme realized and searching for him. The story about 3 Volumes, but I couldn't find the title also mangaka that I've read. Hope for helping.

I'm not quite sure but Koi ga Bokura wo Yurusu Hani seems to fit your description

That's exactly it. Thank you so much for your helping.

You're very welcome 🙂