Man ppl are not simple, they got feelings, and thoughts of their own, they're not like a piece of paper whuch will move according to you , taesoo is a person and he is trying to stop himself from ruining chunwoo, that's what he thinks, he's not a toxic person at all, infact he's a good person
An INFJ, entering college this year, i like cool things, i read bls when I'm bored