Let’s clear this up: Pauly D did NOT get fat. Today he shot back at critics who accused him of turning tubby after unflattering photos surfaced from the launch of Rehab Sundays at the Hard Rock Hotel and Casino in Las Vegas. He wore a lose fitting jersey, and sported a double chin in some photos.

“Ok Just To Clear Up A Few Things ,,, THere You Go !!!! Taking This Morning,” he wrote on his Twitter page, adding a self-snapped photo showing his ripped bod.  He followed it up with another shirtless photo, writing, “Just In Case U Still Confused.”

Did Pauly D gain weight? Yes, but not fat… it’s all MUSCLE.

“He’s gained 20 pounds of muscle,” a source tells Us Weekly. “He is [exercising] nonstop . . .three times a day sometimes.”