She has to fall in love with him first. Only then can he take her heart. And it has to be before he’s 25 and also while they’re in bed together. I think that’ll prove difficult though since he’ll fall in love with her. He might choose not to take her heart and die or who knows, maybe she has two hearts lol. No clue how they’ll solve it without either the ML or FL dying.
I thinks its based upon the concept of, "A peaceful heart leads to a healthy body; jealousy is like cancer in the bones." So the simple fact the basis of this is that they go crazy without having a heart and him being jealous over her heart to steal the a heart is the issue. The whole curse of his father taking the heart of his wife then him being born with not being able to have women touch him is showing that the greed of the generations before was based upon jealousy and is eating away like a cancer to the merfolk. The only way for them to overcome this is to truly fall in love with a human whom they feel is beneath them and him to willingly reject this and accept his fate of going crazy. I only see this for we see a glimpse of her seeing a crazy man in her dreams in chapter 6.
So now they'll try to make her die for him so that he acn get her heart????