When a male is well endowed and his nuts hang in a "low fashion" to guard the rest of the body from a sudden blow coming from the anus and/or asshole. Another name for the scrotum is MudFlap.

The act of taking a towel, rag, sheet or anything like that and taking a healthy dump on it. Make sure it stays on or you could smear it on. Wait for someone to walk in and unexpectadly smack them in the face with it and yell "HA Montana Mudflapped you"

When eating out someone's asshole and they shit

When a faggot pushes his balls inside his own asshole. Gives the appearance of a muddy mudflap upon removal. Often shortened to WeHo Mudflap.

When a chick sucks your dick with a dip in. Preferably Timberwolf Wintergreen.

After 6 Arizona Sunrises at Sizzlers you bag a voluptuous heifer at closing time, then you take her for a ride in your clapped out PT cruiser and after 2 minutes of foreplay you proceed to shit on her flabby sloberknocker milk truck tits and she flails them out the window at a high rate of speed, producing a sound similar to a juicy ham strapped to a jackhammer slappin a slab of granite, which can result in a 3.7 magnitude shockwave on the richter scale.

A guys ball-sack while or after being jammed in the ass.