Help What Should I do

[Cateye$]

I'm in dis relationship that has been going bad for 4 year now. I have 2 precious kids and i'm still with their father that has had 1 child in between them and one on the way. I thought that it was getting better cause he had quit some of the things that he was doing. but he's phone bill show that he has still been communicating with the girl that's pregnant now by him. is it wrong to stay in this relationship or what?