So you got laid? And better yet, you had the good sense to either put on a condom before you bust a nut, or pulled out in time to find a good place to thoughtfully drop your load. Like the boobs, back, face — basically anywhere but.. So you had some fun and got away scot-free. Once your post-coital high wears off and your brain starts functioning at a base level again you might start to hear a nagging voice — no not your girlfriend this time!