The term defining the event where a man and a woman are having intercourse in a bedroom, and upon the time of finishing, a third party who has been hiding in the closet, unbeknowsnt to the man or woman, jumps out and yells "TEN POINTS FOR GRYFFINDOR!!!" and promptly runs out of the room. Usually works best with random hook ups, but also is well suited for sex within a relationship.
"Yo dude, you remember how Chris was with that random girl last night? I so ten points for gryffindored them"
An exclamation used to inform one's friends and acquaintances about a successful hook-up. Only applies to sexual intercourse, although fewer points may be allotted for scoring a base run if the player doesn't make it all the way home. Especially useful if you don't want everyone in the room to know about your sexual escapades.
Person 1: Hey man, where were you last night? We waited for an hour before we left!
Person 2: Yeah, sorry bro, got tied up with that girl from the club. But hey, Ten Points for Gryffindor!!
Person 1: Oh, we're cool then