Were you in love with her, Beast? Did you honestly think she'd want you when she had someone like me!?
~ Gaston

Villains that act as a hero's rival over a love interest. Sometimes they want a hero's love interest to like them but when the feelings are not returned, they'll try to kill the hero and then force the love interest to marry them.

The best example would be Gaston. After failing to propose to Belle and learning she was in love with the Beast, he decided to try and kill him so Belle would be his.