For Judd Apatow, going to work can be a family affair. Not only does his wife, Leslie Mann, star along with Paul Rudd in This Is 40 (the upcoming spin-off of Knocked Up), their two daughters, Maude, 14, and Iris, 10, reprise their roles as Debbie and Pete's daughters throughout the film. While the girls' scenes are filled with typical sisterly arguing and teenage indifference toward their parents, outtakes prove that the apple doesn't fall far from the tree when it comes to comedy. Iris can riff with the best of them, making for some funny behind-the-scenes moments. Check out our exclusive clip of some on-set tomfoolery that didn't quite make it into the flick.