Technically, since Kim Dan left it's been a hot minute (not just for us, but in the narration too). At first Jaekyung realizes his absence bothers him, then he looks for Kim Dan and when he finds him he's become an alcoholic suicidal sleepwalker. This takes him back to his horrible childhood, he also realizes that he's been hurting Dan, that's why he starts to treat him nicely. I may agree that the sex is a bit soon, they could've gone without it, but at the same time it feels like Jaekyung's character development is validated. Also, in real life you can absolutely reject someone, but what can you expect from a manhwa that revolves around this relationship?
Let's set that aside... Addressing this to you. Coz I think only a boomer can make such topic (not in disrespectful way oc). I don’t know why people come here to give life lessons to others. It’s a comment section dedicated to mangas (fiction), idk... It's a waste of time really. Don't mix what people read and what they do with their life
I get what you're saying, but Jinx is supposed to be a "realistic" depiction of life (abuse, trauma, selling your body to make money, fame...). At the same time, we know that it's a work of fiction and therefore the actions of the characters aren't what real people would do in real life. I'd say it's kind of a middle ground between realistic and made up.
OP also wanted to say that the way we react to fictional red flags has a connection with how we react to real red flags (for example, if one "easily" forgives Jaekyung's behaviour, they may forgive real red flags too. Of course, this is not always true and there are many differences between reading and living).
Dan asked for it since day 1. The contract signed his consent away so JK did absolutely nothing illegal or morally wrong. Dan eagerly showered and sprinted to Jaekyung's door. He lost his appetite and felt nauseous because of how impatient he was.
I honestly feel like I'm the only one who understands jinx.
You aren't wrong, but have you considered that maybe you're kinda jumping to conclusions?
Dan never talks about his emotions, we only see his actions: he knows about the jinx, he can't eat when he thinks about it, he showers and he knocks at Jaekyung's door.
Is he doing it because he's afraid or because he likes it? The author doesn't tell us, but we can use the context of the whole manhwa to understand. Dan has had feelings for Jaekyung for a while (some may argue that it's Stockholm Syndrome, but I think that right now his feelings are much more sincere than in the beginning when Jaekyung was his "saviour"), he's also been rejected by Jaekyung and he doesn't know how to accept kindness, so he's afraid too. That's why I think that his feelings in this chapter are complicated, he anticipates and hates the jinx all at the same time.

three instances of him being kind is what makes yall like him? after all he did? yall i pray you guys never get into relationships. relationships are hard work and you have to sometimes put your feelings aside to understand your partner, but with that being said, that does not mean you have to forgive everything they fucking do. And it gets to a point where forgiveness isnt an option anymore.