My dads cheating on my mom?

My mom knows, everyone from my mom side of the family knows now. I don't know what to do? My mother told me the situation, and she doesn't know what to do. My fathers always been like this since I remember, and my mom has always pretended it was nothing. Now Im older, an as much as it hurts me to say this because he is my father: I don't want my mother, me, and my baby brother to live with him.I think it's unhealthy, and I don't like my father(he's hasn't been a good father. Helped somewhat with money but hurts us with his words).how can I tell my mother and eventually my father that I really want them to split up, my mom will definatly not do it without my input, she is to "kind and scared" of a person. She's I think affraid finantually and because she thinks he's sort of a "protection", plus she's thinking of my brother an I. I don't want to move schools, I don't want to leave cheer my friends and everything an awesome small school offers but I mean what can I do? I need to do something!