mechanical advantage 

Making liberal use of vibrators, dildos, anal beads and other sexual devices to make a woman come to orgasm. Used by women in place of a partner, or by a man to a woman because he is too lazy, too stupid or too selfish to do it himself.

Sally wouldn't let me bone her until she came, but thank God for mechanical advantage, eh?

mechanical advantage by Petrodono November 5, 2005

mechanical advantage 

When a machine reduces the amount of force needed to move an object.

A combined pulley jas a mechanical advantage of 2

mechanical advantage by Babshka April 23, 2017