there's a bit of a thing in japan and elsewhere of the "straight" guy who just happened to fall in love with one guy and wouldn't have fallen for a guy if it weren't that specific one. i don't know any ppl like that in real life so idk if it's real but it's a popular trope in BL
I know it does sound dumb but what I think he’s trying to say is that he wasn’t originally gay to begin with. Like he had no prior thoughts of being with men and if it wasn’t for him confessing to him, he would’ve most likely lived as a straight man unlike the Mc who was already gay
I hate it when a gay guy tells another that they are 'not gay'. He's a guy, who likes you. You, a guy. If that's not gay, idk anymore.