Please help: All I can remember is that the main character's lover split up with him because he wanted to see other people and he brought woman around to their apartment and encouraged the protagonist to do the same. When the protagonist brings another guy around however the lover is distraught and seeks forgiveness from the uke for all the pain he brought him.

• kinda similar to overdose but is not it

Warui Yume from Myuzu no Gakuen de Aou?

Thank you 🙂 that's exactly it!