Don't worry about it - worse things have happened. I've made out with a friend like this after a few drinks, when she was still dating her long-distance bf, and it really meant nothing other than that we'd both had a few too many drinks and we are animal beings. She's now engaged to him and they will live happily ever after. And, whenever I see him with her (rarely), I feel bad myself for throwing that little wrench in the works, even though I'm not sure if she ever told him - so if you see the guy, just be mature about it and know that you got the girl, and he's the chump not you.
The bigger question you're going to have to resolve is, why are you dating a girl you broke up with. But that one will resolve itself...
The bigger question you're going to have to resolve is, why are you dating a girl you broke up with. But that one will resolve itself...