Alabama mud flap 

When a man poop's on a peace of paper, rubs it in well and nice, rinses it of with chocolate milk, freezes it for well over an hour, and finally slaps the shit out of his female partner, or vice versa

hence mud flap

B:Oh Henry did you get chocolate milk.
H:Yes. I did Babara.
B:Well why don't give me an Alabama Mud Flap.
H:Well that sounds delightful.

Alabama mud flap by winkyface9 January 1, 2012

Alabama mudflap 

When a woman's inner vaginal lips are SO huge and hang down so low they can actually fold back and rest against the anus, hence giving them a "muddy" appreance.

Vicky dropped her drawers to reveal the nastiest set of Alabama mudflaps I have ever seen!!!! I think I vomited in my mouth a little!

Alabama mudflap by Leonard W. July 16, 2007