when having intercourse in the doggy position, pick up your phone, and call a friend. when you friend picks up the phone, pull out and slip your member into your lovers ass. make sure the phone is close to your lover's face to receive the "yelp" or scream. proceed to hang up the phone, and finish without her knowledge of anything happening.
i got a call from anthony, but all i heard was moaning, then a scream. He must have given her the pitman surprise.