The 30-year-old actress stars alongside Isla Fisher and James Marsden in the new film, about a bachelorette party which spirals out of control, reported E! online.
In one saucy scene, Dunst's character goes wild in the bathroom of a strip club and so she has warned her father to stay away from the film.
"I can't do that to him. I didn't even tell him there was an LA premiere. And I was like, 'Yeah, dad - don't even try getting it on iTunes because you will not like this movie. You're a prude. You will hate it. I know you," Dunst said.