When did you know it was time to leave that man/woman? (Details)

I was thinking about the Guv/Shriver marriage and how Maria had probably put up with a lot before she finally found out about the extent of the damage her husband had caused to their marriage. She must have had that moment of “enough is enough”.

In every relationship that has run its course (through sheer pain or sheer boredom) there is a defining moment when the lightbulb goes off and you say, “That’s it…it’s over.”

What moment was that for you? How did it feel when you made the decision? How did you decide to end it?