You don't have to accept what you don't want, Jiwook hit him because he overstepped his boundaries.
Seungeon is not helping out of the goodness of his heart, or because he wants to see him ok. He does it because he wants something in return. That's not love, that's a transaction. And again, you don't have any obligation to accept anything you don't want. That's called freedom of choice.
This manhua made me realize just how fuc*** up some people morale is. How can you defend a rapist, a stalker and a abuser is beyond me. The biggest mistake Jiwook ever made was give him a chance.