The Jersey Shore star decided to forego the hair gel for the first time in a decade as part of his Halloween costume – he dressed up as Justin Bieber.
"I'll go out with a hat on, but as far as going out in public with no product in my hair, I bet it's been 10 years since I've done that," Delvecchio, 30, told PEOPLE before deejaying at Las Vegas's Moon Nightclub.
With his hair down covering much of his forehead, Delvecchio looked Bieber-esque, but he wasn't entirely comfortable. "It's driving me crazy," he said. "I never go out in public without product in my hair. … It's fun, though."
Ironically, there was no shortage of Pauly D costumes inside the club.
"They're pretty good," Delvecchio said. "They did their research. I saw a few of them, and they had the hair down to a T."