Hello

This is a manga i have read a year ago when i was just starting to get into yaoi
I remember that it was about a guy who wakes up finding a stranger in his apartment, the stranger was quiet and didn't really speak much or didn't speak at all. He then had sex with him and i can't tell if it was rape or not but afterwards he started to abuse him and public humiliate him. I remember that he made out with him in a park full of kids and stuff like that.

The guy probably didn't have a place to go so even though he publicly humiliated him, he still came back to his apartment.

What you described could possibly be "Oh My Bitch!" from Baby Bitch!