I actually like Minsuk a lot because his character is really realistic. Yeah, I think he has a hard time saying no. He even let a werewolf stay in his house (majority of us would have said hell no).I think it goes back to his relationship with his mother. I feel he doesn't want to disappoint anyone. His mother is trying to find him a woman, instead of flat out saying no, or stop, he tries to change the subject (like in chapter 10, he tried to push her attention on his sister and chapter 23, saying that she would be bothering the woman) or he avoids it all together.
Same thing probably happen with his ex, he never said to him the relationship was over. He internalize everything instead of saying it. He doesn't want to hurt anyone. He doesn't even want to come out to his mother in fear of breaking her heart. Bexan is probably the first person he ever flat out said whatever he thought. He can truly be himself with him. That's why I like them together so much, they balance out each other. But, it will probably be a while until he notice that.

Minsuk is highkey a pushover and I’ve never seen it at the start but I’m seeing it more clearly in the recent chapters. This isn’t supposed to be a hate discussion on him but just my observation.
He never seems to reject anyone outright. Like with bexan, he didn’t trust him but didn’t put up that much fight into getting him out. He also can’t seem to say no especially with his mum and he tries to convince himself with words to be able to reject the person but ends up getting pushed by the person he’s rejecting so it doesn’t really end with them.
I feel like Bexan is the one who’ll end up fixing the situation during his “heat” because he’ll lose control once it comes up. Lol