
I wouldn't give specific spoilers, but let's just say that he's on Yvonne's side and trusts her more than Penelope. He's also very very quick to put the blame on her whenever an incident happens. Like, if you think he's already doing this victim blaming now, it's going to get worse in the future.
Also, the only reason he abused her is because he (surprisingly) loves her. He already realized that he was interested in her the first time they met, so he abuses and rejects her to deny his feelings.

@balmy17 here's the whole novel. The translation quality is so-so but it's easy to understand.
https://drive.google.com/file/d/1mRveBcq8L2Uwp0N3WYceMrIfL_Zpemlk/view
i thought her family had a chance of redemption like penelopes family but nope. theyre horrible people. anyways i need to prepare my heart for when Jin gets rejected, we all know its honna happen and its gonna be SAD