If I heard this right, it refers to the action of being sexed half-willing, whether out of obligation or whatever motivation (this isn't referring to rape, mind you). It comes from a movie called Dog Park, and I'd like to see the term used more.
"How'd it go last night? Well, she ninjafucked me."
wearing a black-body suit with only your dick n balls hanging out in a very dark room, drunk ho walks in u tap that shit with your baby dick, and peace out with her having no idea...ninjafucked.
another term for a station wagon, mini-van, or any other kind of vehicle that is targeted at the "family" demographic(also M.A.V.)
"Tactical advantages aside, the M.A.V. is top of the line for the holy warrior troop transport manufactured by the Church of Latter Day Saints Military Industrial Complex. Also great for family trips...to heathen lands."