Adultery in literature

Okay, so you know when Mommy and Daddy love each other very much and they get married? That means they promise to only love and be with each other. But sometimes in books, a character who is married to one person decides to love or be with another person who they're not married to. That's called adultery. It's kind of like breaking a promise. And sometimes in books, it can cause a lot of problems and hurt feelings for the characters involved. Adultery is not a good thing to do in real life because it can hurt people's feelings and break up families. So it's important to always be honest and faithful to the people we love.