Most Embarrassing On-Set Moments

Which star got knocked out? Who ran into an electric fence? And which actress had the displeasure of pleasuring herself? We get big stars to dish about behind-the-scenes drama, naming their most embarrassing moments on the job. -- <i>By Marilyn Beck and Stacy Jenel Smith with Stephanie DuBois and Emily Feimster</i>

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/joan-allen/1026/main' target='_blank'>Joan Allen</a>

"When I first started, I didn't understand how a movie set worked. We were shooting [in a museum] and then, for some reason, everybody left. They were going on to the next scene, but nobody told me. They reopened the museum and these people started walking in, and there I was on this lounge in a negligee."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/steve-guttenberg/29352/main' target='_blank'>Steve Guttenberg</a>

"I was doing <a href='http://movies.aol.com/movie/police-academy-4-citizens-on-patrol/1027550/main' target='_blank'>'Police Academy'</a> with <a href='http://movies.aol.com/celebrity/sharon-stone/68496/main' target='_blank'>Sharon Stone</a>, and she and I were in a hot air balloon. We made a rough landing [and] came down in a cow field. I said, 'I know what to do,' and walked away really forcefully -- right into this electrified wire they had to keep the cows in."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/erik-palladino/240797/main' target='_blank'>Erik Palladino</a>

"I was [playing] a fairly dangerous-looking drug dealer with tattoos all over. My cue was to hide a gun under my T-shirt, [and] next thing I know, three cop cars pull up and have their guns drawn. It took 30 seconds for the film crew to run up."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/dane-cook/271377/main' target='_blank'>Dane Cook</a>

"At the Laugh Factory club in L.A., I was doing a physical comedy bit, and in the bit I had to drop down to the ground. My hand missed the stage and kept going, and my face hit the stage so hard my teeth went into my lip. The crowd thought it was funny until they saw I was bleeding pretty profusely -- I had to get stitches."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/gretchen-mol/223418/main' target='_blank'>Gretchen Mol</a>

"I'm the girl who gets the giggles when things get a little too serious. You feel bad when the crew's been there for 12 hours and everyone's kind of getting a little irritated, but it's hard to keep a straight face."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/david-carradine/84255/main' target='_blank'>David Carradine</a>

"I was supposed to get in a one-punch fight with <a href='http://movies.aol.com/celebrity/chuck-connors/14521/main' target='_blank'>Chuck Connors</a>. He throws a punch and he got me in the jaw. They told me that I was actually knocked unconscious. <i>That</i> was embarrassing -- my debut on film, I was so green. You know this business ... you have to take the bitter with the bitter."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/briana-evigan/465186/main' target='_blank'>Briana Evigan</a>

"I tore the ACL in my right knee. The whole rain segment in [<a href='http://movies.aol.com/movie/step-up-2-the-streets/30381/main' target='_blank'>'Step Up 2: The Streets'</a>] was all done with a big crazy brace on my leg, [and] I actually peed out there in the rain. We were soaking, a thunder storm pouring on us, the bathrooms were really far and it was a struggle for me to go. Everyone knew."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/ralph-fiennes/23390/main' target='_blank'>Ralph Fiennes</a>

"I'm always goofing up," says Fiennes, side-stepping specifics. "I have all the normal actors' fears and neuroses -- that creeping fear that you're f---ing up -- but I keep doing it anyway. I don't believe in regretting even the things I've done that haven't done well."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/jesse-mccartney/346972/main' target='_blank'>Jesse McCartney</a>

"I was touring, doing concerts on the weekends and filming <a href='http://movies.aol.com/movie/summerland-tv-series/1259158/main' target='_blank'>'Summerland'</a> during the week, and I was exceedingly tired. In mid-scene, I dozed off, just passed out. They never let me live it down. They kept playing the clip over and over on the playback monitor."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/tanna-marie-frederick/409878/main' target='_blank'>Tanna Frederick</a>

"My character [in <a href='http://movies.aol.com/movie/hollywood-dreams/29611/main' target='_blank'>'Hollywood Dreams'</a>] gets her picture taken and it gets splashed onto the Los Angeles Times. Her whole thing is to be famous, so this is enormous, [and] she masturbates to the image of herself. That was a little awkward to shoot, with this big sweaty film crew all around and me going at it, to the climax. That's where the acting classes really came into play."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/james-mangold/101021/main' target='_blank'>James Mangold</a>

"What happens to me is, I'll have my headphones on, watching the monitor, and then get so caught up I run up to talk to the actors and forget to take my headphones off, and end up carrying the entire video bay with me, dragging along cameras and wires."

Most Embarrassing On-Set Moments

<a href='http://movies.aol.com/celebrity/johnathon-schaech/197736/main' target='_blank'>Johnathon Schaech</a>

"When I did <a href='http://movies.aol.com/movie/that-thing-you-do/2805/main' target='_blank'>'That Thing You Do,'</a> I sang the song [on set], and I'm not that great of a singer," recalls Schaech, whose voice was later dubbed into the film. "Playback would be bursting out of the speakers, and they would laugh! Even [director] <a href='http://movies.aol.com/celebrity/tom-hanks/93341/main' target='_blank'>Tom Hanks</a> was on the floor laughing his<br>a-- off."