
I can't remember what this is even about

Basically about a vampire, princess (i think)and a knight and one more character who reincarnated in the modern world where they're no longer needed since the times are different. The vampire kinda is obsessed with knight(i think due to his blood), slowly they grow closer and the story just ends on some cliffhanger without properly disclosing their relationship.
Starts off good and ends kinda okish

Ok mc why believe him

Why wouldn't he? The ml has done nothing but manipulate Yujin from the start. He blackmailed and threatened him into marriage, using his son both as bait and collateral, while also abusing him via pheromones and forcing him into sex. You'd have to be an utter fool to think he has done anything even remotely trustworthy. He's only being nice now because he thinks Yujin has nowhere else to go and is properly chained both by his marriage status and his son. Abusers always seem so nice when you play into their hands and ml is no different. It's when you wake and take a good look at their behavior that things get rough, and Yujin is in for a hard time.
now why would she yell that out ughh hate stupid bitches Σ(っ°Д °;)っ