Yo,
So I am looking for the title of this manga.

Gay dates a straight guy who cheats on him with women. I guess they've been together for a year or two; that dude continually closed his eyes, but eventually he snaps and leaves him. He even dates another guy but that womanizer gets ill or sort of and they end up together again.

Thanks for your help

Is it Overdose?

OMG!
Yep,
Thanks a bunch!!!! 🙂