Similar to motor-boating, mud ruddering involves grasping each side of the buttocks, gently spreading the cheeks and placing one's face on the poop shoot; then shaking the head back and forth as if saying "no" while proceeding to make a motorboat sound. Essentially, the buttock cleavage equivalent to motorboating. Unlike motorboating, mud ruddering makes no sex distinction, as you can mud rudder anyone who has buttocks.
Johnny saw that Sally's breasts were quite small, so he decided to mud rudder the hell out of her.
by Scotty By Nature December 13, 2011