Someone he had previously given a note to showed up. The uke was wearing the blindfold so he didn't realize it wasn't Oak. He kind of felt like something was off but by the time he fully finally realized it, it was too late. He didn't do it on purpose like before, it truly was a mistake and he felt terrible about it because he finally realized he really likes Oak. The story is good, don't give up on it!
Rape implies that the other guy forced himself on the uke. He didn't! He did exactly what he was asked to do when he was given that note. It was a misunderstanding, pure and simple. I feel like now everyone is going overboard with the rape thing. He was drunk, rape! he says during sex: It's too deep, stop. Rape. He was half asleep, rape. He didn't look him in the eyes when he said yes to sex, rape. He sneezed on him and got his fluids on him, rape.

so we're going to pretend that the uke wasn't fucking with another guy before ml arrived? oh okay