Nikki Blonsky claims Zac Effron "slipped his tongue on [her]" when they filmed a kissing scene for 'Hairspray'.

Nikki Blonsky

Nikki Blonsky

The two stars became firm friends when shooting the 2007 musical but the 32-year-old actress - who played Tracy Turnblad - admitted director Adam Shankman had to stop filming when her co-star took a chaste lip lock near the end of the movie too far.

Speaking on the 'Women on Top' podcast, Nikki said: "Zac and I stood there for nine days. It was great. He is magic. He is a very talented man, all in all. He’s got it all, what can I say?

“He slipped [his tongue] on me! 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!'”

The 'Queen Sized' actress - who came out as gay earlier this year - admitted she and Zac spent as much time together as possible while shooting the film because they always had "the best time" together, and she would even do his chores because she got tired of seeing his dirty laundry.

She said: “Not to make every woman and gay man jealous, but he was my best friend on the set of 'Hairspray'.

"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!

“I would be like, ‘Listen, buddy. How many piles are over there? What’s going on?' “I love him.”