Most guys getting dressed in a communal setting seem to just pull up their underwear and let the parts go where they will.  However, if you do that in a dancebelt, it can be a major discomfort!  Mid-performance scratching and tugging would be extremely bad form.  Therefore, when you put on a dancebelt, it is important to get everything positioned properly.  Once you leave the dressing room it isn't going to get any better if something is driving you nuts!  Most dancebelt wearers realize this, so it isn't uncommon to see guys tugging and poking as they get everything settled and comfortable.

Backstage is not a good place for modesty, but you should be able to find a place to get into your dancebelt without it becoming a public spectacle.