Jennifer Lopez' #1 Husband -- Pounding Out Full-Frontal Playgirl Deal

He was Jennifer Lopez' first husband ... her first divorce -- and now, nearly 15 years later, he's a few signatures away from becoming J.Lo's first ex to whip it out for Playgirl magazine.

A rep for the adult rag tells TMZ, it's true ... Ojani Noa and Playgirl are currently hammering out a deal for J.Lo's first ex to appear in the magazine -- but ONLY if he agrees to go full-frontal.

And as long as Playgirl ponies up, that shouldn't be a problem -- Ojani tells us, "If the money is right, especially for full nude, then I would be flattered to pose for Playgirl."