https://www.mangago.me/read-manga/red_area/
It's been a while since I've read this one, but I'm like 99% sure that the MC cheated but they still ended up together. He was insecure or smth like that.
The story and plot good?
The troupe is strangers to friends w benefits, if I remember correctly. The plot and story are definitely there, although I wouldn't call it perfect or amazing.
The plot is focused on the MC's and ML relationship without any outside interference (again, if I remember correctly). The MC hands handsome strangers a note in passing with a time and place to meet for sex. He meets this one man, who he chooses based on his hands, in a hotel and they have sex.
I can't remember much of it, but they do continue to meet up for sex after that, and the MC wears a red blindfold so he doesn't see who his partner is. But the ML become a bit obsessed with seeing the MC's face.
Like I said, it's not a 100/10 plot, but I thought it was pretty good.
Any yaoi where one of the mc was caught cheating, they fight and still end up together?