Pop diva Madonna was spotted Saturday in the audience at New York Theatre Workshop’s provocative show “Slave Play.”

A spy quipped, “If you’re wondering what it takes to get Madonna to go to an off-Broadway show, apparently full-frontal male nudity doesn’t hurt?”

One review of the show called it “very R-rated.”

We hear the Material Girl brought daughter Lourdes Leon, 22, and was lured by the show’s positive reviews, “not to mention the well-displayed anatomy of star Paul Alexander Nolan,” the theater spy said.

We hear Madge was overheard saying she wants to take daughter Mercy to see “Beautiful: The Carole King Musical” on Broadway.

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