
It's not about whether Kim Dan offered it or not, basic human decency is that you treat your partner(in this case the person you're having seggs with) with respect and care, but tell me a chapter where Jaekyung's main intention wasn't to just ruthlessly fuck Dan. Thats why we hate him, it's alright if you don't though but I just hope u get why what he's doing is wrong :)

Consent is not limited to what the person says. It considers the situation they are in. A simple exercise you can do is asking yourself "would they have offered/agreed if they were in another situation? (not depressed, not coerced, not broke, etc)". If the answer is no, then they didn't actually consent.
I just don't have a real reason to. Kim offered it..?