Here's another stunt I did myself on the set of Vacation Movie. As you can see, I'm basically immune to fear. | Ed Helms

actors messing up on Instagram: "Behind the scenes of The Hangover, even the wildest scenes get derailed by nonstop laughter. Zach Galifianakis unleashes unpredictable lines, Bradley Cooper breaks instantly, and Ed Helms can’t finish a take without cracking up. Every attempt at delivering straight dialogue turns into chaotic comedy the second someone slips or smirks. Props malfunction, timing unravels, and party scenes collapse when the cast goes off-script. Galifianakis’s awkward brilliance and