similar to a "golden shower," where one urinates on another during sex. This name references Robert Mapplethorpe's famous artwork "PissChrist," where the artist pissed in a jar containing a crucifix and took a photo of it.
While Ted was banging Brenda, she told him "piss on me!" So he pulled out and gave her a Mapplethorpe.
by Mick Fly November 07, 2006