While performing deep downwards thrusts into a females ass, usually while she is laying down on her stomach, reach under her hips from the outside and massage her vagina, while she is experiencing intense feelings, shove a pre-cut lemon into her vagina.
Guidelines: Make sure you are about to cum, or do it while you are cumming, as she will probably resist this action and become very pissed and you'll want to get your nut off in time.
Also, remember to sit your lemon in a handy place.
This can also be done with a lime.
Guy 1, "Remember that girl Hannah that works at Amber's daycare?"
Guy 2, "Hahaha I heard she was a slut"
Guy 1, "I totally gave that bitch anal with a twist last night."
Guy 2, "Is that why your car has a busted window??"
Guy 1, "Totally worth it."