The act of eating a hard shelled taco while receiving a blowjob. The giver may or may not know that a taco is being eaten. Often results in over excitement which leads to premature ejaculation.
She was trying to keep the fact that she gave a blowjaco concealed but going down the walk of shame with lettuce stuck in her hair was a dead giveaway.
Person 1: "Hey man how was last night? Did you get any?"
Person 2: "Yeah, I hid a taco by my bed so I snuck in a blowjaco while my cock was in her mouth."