As one of the kids, how do you act when your parents seperate?

I think my parents are getting separated. My mother is living with me and my two sisters in New York, while my father is in North Carolina. Every argument has two sides, but a lot of the blame falls on my father for everything he did to my mother. My mother finally couldn’t take it anymore and left (that’s why she’s here).
My father hasn’t actually done anything to me. I do resent him a little because he hasn’t been like a traditional father to me. Aside from a few times, I always thought that it would make no difference if he were gone from my life.
The thing is that my mom thinks that I should talk to him because he didn’t do anything to me; I’m not the one fighting with him after all.
I don’t know what to say to him if he did call me (which he doesn’t). I was never close to him.
Have any of you ever been in this situation? How did you handle it?

I’m sorry if this is personal, but I can’t really talk to my family about this. They are all dealing with it and they don’t really talk to me about it. I’m the youngest of five kids, so what do I know right? I can’t help them, so I don’t talk to them about this.