Ok, as an update.
I decided to tell my girl about it.
She then goes on to tell me that her and her roomate have had 3ways with other guys before, so maybe her roomate thought nothing of it.
She also told me that she didn't want to do that with me and her because she really liked me, and did not want to complicate things. (I didn't even bring up the 3 way thing, she just admitted to it)
So I guess I got two options
#1 Be happy my girl likes me and leave well enough lone
#2 Go bang the hell out of her hot roomate and next the two sluts
What do you thimk?