Kind of cousin of the Dirty Sanchez. Here, while banging a girl from behind, stick a finger up her ass and get some poo on your fingertip. Then put a little on another finger on your other hand. Right when you cum, rub a finger under each of her eyes, giving the appearance of an athelete's eyeblack, and then yell "First Down" and make the hand motion a football ref makes for a first down.
Last night I was giving Meg some doggy action, and gave her a Dirty First Down. She loved it.
by Dirty First Downer June 29, 2009
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a code word used for when parents will be out of town on the last day of the month (usually the thirty first) and a party is going to happen
by don'tbeTHATguy August 2, 2010
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