The former "High School Musical" star played Link Larkin in the big-screen adaptation of the hit musical, opposite Blonsky as Tracy Turnblad. After an illicit romance throughout the film, Link and Tracy finally share a kiss towards the end of the movie - but Nikki revealed on the "Women on Top" podcast that the moment nearly got them a PG-13 rating due to Zac.
"He slipped (his tongue) on me!" Nikki laughed. "Adam Shankman, our director, called him on it. Adam was like, 'Hey, whoa, just caught the tongue!' And Adam was like, 'No! No tongue!' He's like, 'This is PG, there is no tongue!' "
Nikki went on to reveal that she and Zac became firm friends while shooting the film, which was released in 2007.
"Not to make every woman and gay man jealous, but he was my best friend on the set of Hairspray," she smiled. "Even when we weren't filming, we were together on the weekends. (He was) constantly at my apartment and I was always at his, doing his laundry when he didn't do it. I will toss him under the bus for not doing his laundry! And he knows it!"
It went on to receive three Golden Globe nominations including Best Actress, Musical or Comedy for Nikki Blonsky and Best Supporting Actor for John Travolta. It also got a Grammy nomination for Best Soundtrack Album.