To be fair, Jin IS communicating. He put on effort to talk to Hamura, asked what’s wrong and tried to apologise. Like a normal person would.
But unlike a normal person, his problem is that he lacks understanding of other people’s feelings OR he just likes toying with those two.
Either way, he is still a cheater. Not cool.
in what way he try to communicating? did he actually think what he is doing is okay in any way, shape or form? and he knows Humara has problems with self-esteem, even in the past the asshole to choose to say the one thing that will hurt Humara so badly with words that it made him snap at him! yet he dares to blame him with cheating while he himself cheats with no shame?! communicating my ass!!

*insert all the eye rolls here* How tf is this relationship supposed to last when one person has the communication skills of a 6 year-old, and the other thinks it's okay to kiss and cuddle other men in bed?