Responses

Lol what.
It's an alter ego, not a different human being. Comparing it to a twin, who is a completely different human altogether is dumb.
I get people can feel like he's cheating but it's literally the same guy.
When you grow up you change into a different person, too (some more than others) so you wanna say your partner should break up with you because you changed while growing up and they would be cheating on your younger self? Lol
Hating on the uke because he literally likes all of the "personalities" of the guy he likes is a bit unfair I think ╮( ̄▽ ̄)╭
I'm not liking the uke anymore~ that's obviously cheating. His reason is because they have the same face, body etc. So what if it's not an alter ego but a Twin will he have sex and flirt with Rei's twin too?
The reason Rei is insecure is because of he half hearted rejects Kazuha but flirts with him.
Why don't he imagine if he has an alter ego completely different from him and have sex using his body with his boyfie. He'll feel betrayed too.