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!
Imriel, Melisandes son is the mc of the second trilogy, which takes place a couple of years after the first trilogy.
Phedre and Joscelin gets mind controlled into antagonists by the real villain. All of Melisandes past crimes are pardoned and is regarded as a hero, even though she never had any come uppance or prison. She always had power and influential within the church, is in a happy relationship, gets to reunite with her son and together they save Phedre, Joscelin and the world.