666 might be the Number of the Beast, but the good folks at Grouper think that just plain 6 is the Number of the Beast with Two Backs. Launching their first Austin outings next week, this matchmaking service started by Yale alums encourages its paired-off users to each bring along two wing-people, the notion being that, while one-on-one dating offers two possibilities -- one of them bad -- three-on-three encounters offer so many possibilities you'd have to be a mathematician who never goes out with anyone to figure them out. Apply for membership, and they'll vet you via Facebook-stalking and a few simple questions that won't be seen by your mom, though you can consult her on your answers. If you're accepted, they'll analyze your zen-garden of a profile and match you with someone who shares your interests, ideally in your age range unless, say, you're into older women and she's into being objectified as a North American big cat. Then you, your potential mate, and all four wing-people toss Grouper an Andrew Jackson in exchange for a reservation at a partnering bar (Lanai, Trifecta on 3rd, Firehouse Lounge, to name a few) and a gratis first drink, including tax & tip -- because the last thing you want to do on any kind of date is stiff your waitress and have her turn into an Iron Maiden.