Resentment can destroy a relationship.

It starts as a small, annoying, secret pinch.

If it's not addressed, it will grow every time you see an ambiguous signal, making you resent more, distrust more, and be more primed to view future ambiguous signals as proof of what you resent.

Resentment can grow from a small pinch to a crushing weight making it impossible for anything to grow.

Once it's gotten huge it's way harder to deal with.

Deal with it when it's just a pinch.