It's because it was painful to see him since he through that he had someone else he liked.
But even before he thought that he seemed extra resistant to the relationship or resistant to a deeper relationship I guess I should say
It’s his personality. He was supposed to be that flighty sort of guy who’s always joking and never taking anything too seriously. He wasn’t prepared to actually fall in love with Sensei and it went against all his past relationships. His character is supposed to be childish so he wasn’t really ready to accept this adult relationship. It was fine when it was just fooling around at first and just getting to know each other but once the ex came into the picture, it forced him to kind of re-look at his own feelings. That’s why he couldn’t just agree when the Sensei said they only had a physical relationship, because it wasn’t true but he should’ve said yes according to their relationship and his personality, but he couldn’t because he was in love and he couldn’t admit it.
Oooh thank you, that makes more sense. I love this manga btw
I was always a little confused on why Tanihara was so resistant to committing to the doctor. He didn't seem to have a problem with the homosexual aspect of the relationship and he enjoyed the doctors company and always thought about him when he wasn't around so what was the problem?