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1.) The art of buying a Mcdouble at McDonalds, going to the bathroom, splitting the sandwhich, jizzing on a patty, and going up to someone whacking them in the face with both ends of the McDouble.

2.) When A male gets a casual Handjob in McDonalds from a random female.

Originated In State College, from the Classic S.S.F.
1.) "Oh my God, Leanne just got a McWhack-Attack from that guy in the panda suit!"

2.) "Every Friday, I got to McDonalds SMASHED at 3 in the Morning and get a McWhack-Attack from all the prostitutes.
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