Let’s say you do something wrong in a relationship. You know it’s wrong, and the other person knows it’s wrong, but they let you get away with it. It’s wrong, but it benefits you somehow, at the cost of the other person.
There’s now a tiny window where this wrong thing is just a wrong thing: if you miss this gap, it will become a habit, and soon, it will be part of the relationship, and it will be a massive struggle to fix it.
Are you in the middle of a tiny window right now? Maybe you should apologize, and close that window.