ah, yes... similar to my current situation at school (shit spreads like wildfire).

Best bet is to be upfront about everything that happened, and act as if it was casual. If you can hold your frame that way, other people will slowly begin to adopt it as well.

And next time you should assume that people in small groups are going to talk. Sleeping around your social groups is a COMPLETELY different game than knowing you'll never see a girl at a bar ever again