Dance belts were invented for a reason, not just because someone decided it would be fun to have male dancers wear strange, uncomfortable underwear that gives them a huge bulge in their tights.

The #1 reason is to keep the male apparatus up and away from the strong inner-thigh muscles.  Several ballet moves like beats, sous-sous, and 5th position involve a rapid crossing of the leg.  You don't have any opportunity to move your parts out of the way if they are trapped in the "danger zone" between your legs.  In the worst case, they get semi-crushed, but more likely your testicles just get jammed into the body cavity from which they emerged when you were a boy.  This is not only uncomfortable, but can give you the symptoms of an undescended testicle.  These symptoms include

-testicular torsion.  The testicle gets tangled with a blood vessel and can strangle and die if not promptly treated.-increased risk of testicular cancer.-infertility.  Not only the short term caused by elevated temperature, but killing off the cells associated with sperm production.-possible increased risk of inguinal hernias.  Doctors are divided on this, but as long as I'm listing risks, I put it down anyway.

When pulling on your dance belt, you should reach into the pouch, grab a handful of scrotum, and pull up.  This insures nothing gets caught under the edge of the pouch (ouch) and gets your testicles positioned in the dance belt so they can't retract.  In a crowded dressing room, some guys may think this looks like they are playing with themselves, but if you look around, the others are doing the same thing.  Once your dance belt is on, with everything properly positioned, your parts are locked in place and you shouldn't have to readjust.