Sex and imagination...

I've been having sex with my ex boyfriend because we're trying to work things out for our daughter. We're not officially together but still.

Anyways...the only way I get in the mood is if I think about the guy I was with before I got back with him. I'm trying to fall for my baby daddy again but it's hard because we hadn't been together for four years and this other guy and I just didn't work out but I fell hard for him. Anybody else had a similar problem?