The situation which occurs when one consumes an adequate amount of tacos or taco accessories to have sufficient indigestion, poop, and in some rare cases amnesia and spiderfingers.
The act of a guy having sex with two girls at once, one with his own junk and one with a strap on dildo attached to his back just above his butt. The male thrusts back and forth in the middle pleasing both lovely ladies at once.
Brian: dude i totally had a double taco last night with that one four fingers chick and her sluttly friend. It was so awesome
Luke: dude thats pretty sweet i wish i could have a double taco with two scene chicks. It sounds like fun and im super desperate.