You’re reading a romance novel or one with a major romantic subplot and then the designated love interest of the female (or male) protagonist does something that hurts the protagonist and you hate them for it, and wish they didn’t end up together… but sure, they end up together.
Due to the nature of this discussion, spoilers from the books are included.
Example of how to write:
Gideon de Villiers from The Ruby Red Trilogy.
>!spoiler here!
Angel Clare in Tess of the d’Urbervilles. Screw Angel Clare. I’m still mad at him 30+ years after reading that book.
This is the best answer.
He deserved a lifetime of nothing but regret and pale imitations of memories after how he messed up with Tess.