It's unattractive. It's dumb. But I do it anyway. Just cuz I can, and most people can't.
A couple of weeks ago, a bunch of friends and I were having beers on a patio. Some of the guys were talking about how they could fold their tongue in half, so - of course - I had to one-up them all. Long story short, we shot a video tutorial so everyone can learn to be a loser like me.
Enjoy responsibly. And please keep in mind that this is probably around 1am. At a bar. A bar with beer.