There is a line that has to be followed; however, the pros are paid to entertain... I would exclude grabbing genitalia, cell phones hidden in the goal post pads, and Sharpies in the socks.
As I have said and will say again, act like you have been there. In HS, making a good play, running to the visitors bench and doing "Rock the Baby" and grabbing the cods will get you membership in the Stadium Club!