I didn't really get that they were in a relationship though ... just that he was his HS crush or something so wouldn't technically be cheating would it? but then it is unclear who exactly is txting him on the phone.
They're not in a relationship. At least not yet. Ayato just saw Kouhei acting really tense around a guy and pick up the hint that the guy must be forcing Kouhei. So he use the fake boyfriend maneuver to save Kouhei.
Ayato probably doesn't know that Kouhei is gay and only thought that the guy was being forceful. Since they were best buddies, Ayato is only trying to reconnect with Kouhei as a friend. And looking at things, it's probably Ayato who text Kouhei.
i read nigai no theme before this lol, it was so weird
Oh, no they’re not dating or anything. Just former BFF I think?
But I was just “triggered” by the word cheating, because the manga I read before this one left me sad, traumatized you could say
Yea same! Came here straight after reading tat one. So the word cheating is triggering
Som spoiler for another manga called Nigai no thme
After reading Nigai no Theme, anything about cheating hurts me heart to be honest.