Despite sounding like a rough burger you might pick up at your favourite hang out, mcjizzy is a term used to describe the act of getting in with a friend and due to overexcitement and loss of control, jizzing your pants.
"She stuck her tongue down my throat, and left me in a right Mcjizzy moment"

"whey, MCJIZZY"

"oh shit! i think i'm about to do a mcjizzy"

"mmmm Katharine, uh uh MCJIZZY"
by Jella July 15, 2009
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