Here's the thing, though: If a provider wants to ask you if you are a cop, be honest and say "no". if she wants to do a "cop check" by having you grab her boob or flash your willy, go ahead and do that, too. Don't explain to her that she is being silly and those things have absolutely no effect on the police. Either she will get defensive because "Everyone knows that you have to do a cop check" or she will get nervous that you know so much about cops and you aren't answering the question.
Just smile and play along and let her touch your ding-dong to "prove" you aren't a cop.
Also, some fun related links:
http://tvtropes.org/pmwiki/pmwiki.ph...ateIfYoureACop
http://s166.photobucket.com/albums/u...ent=hooker.mp4