MacMillan

The act of shoving your testicles into the anus of a girl you are having vaginal intercourse with in the missionary position.

May also include shoving your testicles into the vagina while having anal sex.

Akin to an "Armstrong".

"Dude, I was doing this chick and I totally MacMillan'd her. Right in the backseat of my Miata!"

by TroubledIndividual March 26, 2009