Honest, I'm sure the idea looked great on paper. It sounds like something Dean would do. If he was a virgin on his last night on earth, he'd want to get laid, so why can't the same rule apply to an angel? Still, when it all went down, even Castiel's completely freaked out look wasn't enough to save this clunky whorehouse scene. It would have been better to happen off camera. Dean may have been laughing, but I wasn't.