A) No, the pants can be lowered to knees, ankles or removed completely, by no nudity I mean the top part is always covered by shirt etc: For me this scene has nothing to do with naked bodies, pornography or viewing any other part of your anatomy other than your bottom, not only that full nudity can be misconstrued as a lewd act.
I particularly hate guys who think their penis is held in high regard and send me photos of it, please don't bother they will just be deleted as will your E mail, I have no inclination to even view such photos and it is such an ugly tiny part of a body!