People who fuck together. You may not I repeat may not have a "date" with this person. As soon as you use the word date hell will freeze over. This is for girls who you are too embarassed to take on dates, but you secretly wish to bang her over and over again. Hanging out is optional. It is basically friends with benefits minus the friends part. Prostitute, Booty Call are basically the same although the prostitute part minus getting paid for it. Its a secret relationship!
Tiger Woods has had several simple relationships, but he started buying them stuff and then it just went downhill from there.