Would you stay or Leave?

Katrina
A friend of mines was in a casual relationship for a couple of years..I say casual because they weren't exclusive. Eventually she became pregnant,because they were both seeing other people he asked for a DNA test.She did the test while 6 months pregnant and it was his baby.She moved in with him and stayed until the baby was about 3 months before separating.once she decided to go back to work,he suggested a female friend to watch the baby.She was out of work and could use the money.come to find out they had been sleeping with eachother for years and were in a relationship.he had his new girlfriend watching the baby..since then he and the woman have bought a home and are engaged to be married..but my friend can't let it go...5 years later..she has harassed this lady,went to her job and home to try to fight her.she calls and texted her being very disrespectful and calling this woman's kids bastards..yet her son spends more time there than with her..my question is if you were his woman what would you? After 5 years of being disrespected? Is the love strong enough to continue to deal with the drama? Or do you move on for your own peace of mind?