Sorry. I accidentally pressed post before I finish. So basically they make all these bets (or promises) with each other since they were in high school, and the light haired one wants to break up all the time because he’s worried that his partner is already bored of him (I think they’re both 36 so they’ve been together for a long time). He usually dresses very sloppily but one day he dresses up very nicely and visits his partner’s workplace and then proceeds to have sex with him in front of the girl that has a crush on his partner. There’s a huge surprise at the end (I don’t want to spoil anyone who wants to read it lol). Sorry I just remember the manga in bits and pieces but I hope it makes sense
I’m looking for a yaoi manga i’ve read quite a while ago that I can’t remember the title now. It’s a slice of life about an established couple, one with hair and one w/ light hair. The light haired one is an author (I think) and the dark haired one is the heir of a wealthy family(?).