When a person that is getting made fun of, has nothing but untrue, off the wall and outright ridiculous comebacks, which are completely unfunny as well as make no sense.
"That made no sense at all, you totally pulled a mccaffrey on that one."
When a person receives a Blow Job inside or around a trash/garbage dumpster with whipped cream, by an inexperienced female.
"Did you get a mccaffrey from your new girfriend?"
When a grown man has to run away and cry for help to a bigger and/or tougher man to come to his aid, to help him with his problems with his bullies/friends. Once the bigger/tougher man is done scolding the bullies, the said, mccaffrey will then come strutting back to the room acting as if nothing had happened.
"Oh look he is crying, he is probably going to pull a Mccaffrey now..."