Sex with your best friend.

I just got out of a long relationship. Like almost the ten year mark long. I've never considered my best friend as anything more than a best friend. Sure we flirt, but neither of us takes it seriously. Anyway, we had sex. So far it hasn't changed anything. It's weird, but if anything has changed it's that I feel THAT MUCH more comfortable with him. Neither of us want to be in a relationship (considering we both just got out of bad ones) and we both like each other a lot. I mean, we ARE best friends. Still...this kind if thing is new to me. So I'd like to hear what others think of the idea.