When a man cums on a woman'sasshole and lets it dry, thus creating a covering over her hole resulting in a "flap" of dried seminal fluid the next time she takes a shit.
Hey bro, I gave my girl a Mississippi Mud Flap last night, that shit was savage 😂
A long, thick and voluminous mullet, found on the beautifulredneck of Mississippi. I liken it to a lion's mane, only much prettier when observed in it's natural habitat.