Kids can be very cruel. She should have told Yuu right then and there, she didn't know, I mean she could have checked in with her but I'm sure the other two girls deceived her somehow
What is he gonna do in the long run ? keep dicking her down every second they're together until his dick falls off ? keep her on a leash ? this guy is pathetic to fall in love with a girl like her, even she was like "why"