Overalls and jumpsuits are pretty cute, particularly on gals (cancel me already, don't drag it out, I've got a lady mechanic fetish, deal with it).
Anyway, the idea of an article of clothing you have to completely remove/lower to have a piss seems a hassle.
At a music festival, in an all in one or dungarees, I'm not hugging you, no matter how long its been. Keep your piss straps away from me.