One has to chuckle a bit at the sight of, in a single breath, getting borderline pedantic about the proper name for the region between anus and scrotum or vulva, and then using the term "thingy" ;)

Referrence materials on hand at the moment, in all their general glory, would seem to point to either term being acceptable in casual conversation....as well as bring to mind hurried, husky whispers of "Push my choad."