A Retrograde Wheelbarrow is where the female places her hands on the ground to support herself whilst the male picks up her lower body and thrusts into her, mimicking a wheelbarrow (with extra sex).
A Retrograde Machinegun Wheelbarrow is the same, but the female places her hands onto a machine gun emplacement and fires, causing vibrations to resonate throughout the female, and into the male, resulting in increased pleasure for both members.
May be performed during actual defence of a position for extra tension.
The Soviet Army 1939-1945
I'm pretty damn sure the Retrograde Machinegun Wheelbarrow (or "Machine Gun Fucking") occurred then.
The cravass-like orifice between the female genitals and the anus. It has the purpose of excreting a translucent, odourless liquid that shrinks the testicles and turns the scrotum into mush if the female partner is displeased DURING intercourse.
WARNING: This varies from woman to woman but however statistics show that 1 in every 8 teenage females periodically experience this over 16 months. Eventually it will dry up and make the orifice unused apart from when it participates in Oral Sex and when the penis goes off-course.
Sam was doing great until he phoned Travis to tell him he was engaging in intercourse. Needless to say my pnochria went off and withered his manhood to viscious goo.