Pete and Debbie's lives are falling apart — and now they're both turning 40. Paul Rudd and Leslie Mann star in This is 40. Now on Netflix. | Netflix

Bloopers from This Is 40 showcase how improvisation played a huge role in the film’s comedy. Judd Apatow often let scenes run long, encouraging actors like Paul Rudd, Leslie Mann, and Megan Fox to experiment. That freedom frequently caused takes to collapse into laughter. The outtakes are memorable because they reflect the movie’s loose, conversational style, where the funniest moments often came from lines that were never meant to stay in the script. | Unforgettable Bloopers

Paul Rudd and Leslie Mann's total inability to keep a straight face during Melissa McCarthy's improvised two-minute rant in an outtake from This is 40 remains endlessly watchable | Netflix