pelvic muscle
A muscle used to thrust the shaft of the penis into the vagina.
'Mommy, how come when you and dad make a lot of noise in your room, after there are always imprints on the ground?'
'Oh sweetie, its because of his pelvic muscles...and the fact that i weigh 300 pounds.'
'Oh sweetie, its because of his pelvic muscles...and the fact that i weigh 300 pounds.'