2257 does not apply to non-sexually explicit nudity. It is not the same test as obscenity, so crack is OK. Full frontal nudity does not trigger 2257 either, male or female. Masturbation and penetration is ALWAYS covered by 2257, so if you have a guy holding the high hard one, it appears he is masturbating and in my opinion, 2257 applies. An erection alone is where you will find reasonable minds differing. I tend to believe that an erection alone is not sexually explicit as long as the guy is not touching it.