1. Keanu Reeves had an explicit threesome scene with the director's wife while filming Knock, Knock. Tap to play or pause GIF Tap to play or pause GIF Lionsgate "I mean, those scenes are always weird," Reeves said. "But Eli [Roth, the director] created a great situation of trust in rehearsal...but eventually you've got to strip naked and simulate, and I wasn't going to be that guy who was like, 'Hey Eli, your wife's hot!' Yeah no, he was really cool about it and we all...had fun." 2. Margot Robbie ended up with paper cuts on her back while filming a sex scene on top of fake money in The Wolf of Wall Street. Tap to play or pause GIF Tap to play or pause GIF Paramount Pictures "I got a million paper cuts on my back from all that money. It’s not as glamorous as it sounds," Robbie said. "If anyone is ever planning on having sex on top of a pile of cash: don’t. Or maybe real money is a bit softer...when I got up off the bed, I turned around to get my robe and everyone gasped. They said, 'You look like you’ve been whipped a million times." 3. Dave Franco's unfortunately timed butt pimple on the set of Neighbors made his first-ever sex scene even MORE awkward than it needed to be. Tap to play or pause GIF Tap to play or pause GIF Universal Pictures "I was pretty nervous for the scene. I met [Halston Sage] the day before, and she was beautiful and very sweet, but it's awkward. You meet each other and then you're grinding — you don't even know her name, barely," Franco said. "And then, of course, I woke up that morning and I had a giant pimple on my ass. I had to go to the makeup artist who I had ALSO just met that week and be like, 'Can I go in the other room and have you put makeup [on it]?'" 4. Aubrey Plaza wanted to break the ice before her sex scene with Robert DeNiro in Dirty Grandpa, so she slipped an "incredibly slutty picture" of herself into a book and gave it to him as a gift. Tap to play or pause GIF Tap to play or pause GIF Lionsgate "I didn't know him, we had never talked and I was really scared of working with him. So I was like, 'I'm going to do something kind of crazy,'" Plaza said. "I took an incredibly slutty picture of myself in character, put it in a book about Zen Buddhism, and slipped it under his trailer door. I didn't hear anything about it for a week, so I was terrified that I was going to get fired. Then, he casually came over to me a week later and was like, 'I got your book...' — and I had put the photo on page 4, so then he said — 'I only got to page 4, but it was VERY good.'" 5. Jamie Dornan would make goofy noises instead of faking orgasm to make Dakota Johnson laugh during the more intense sex scenes in Fifty Shades Darker. Tap to play or pause GIF Tap to play or pause GIF Universal Pictures "When there's a wider shot and we're going for it all in one piece, they'll play music over it, and it's always my temptation to make Dakota laugh," Dornan said. "So sometimes, I'll do things like — in a moment when I'm meant to orgasm — I'll instead go, 'Doo-doo-doodley-do!'" 6. Alison Janney and Michael Lerner were so slippery during their steamy scene in Life During Wartime, it sent Lerner to the hospital. Tap to play or pause GIF Tap to play or pause GIF IFC Films "Michael had to push me up against a wall, and they wanted us to look sweaty for the shot. So they sprayed this glistening stuff all over us. They didn’t realize that we’re on a marble floor," Janney said. "He pushes me up against the wall and — all of a sudden — we drop out of frame because he slips and he drags me down with him. He falls on his knees and I can’t stop laughing...and the cameraman couldn’t stop either. But [Michael] really hurt his knees. He had to go to the hospital." 7. Robert Pattinson's buttcrack caused the sex scene in The Twilight Saga: Breaking Dawn – Part 1 to be recut before release. Tap to play or pause GIF Tap to play or pause GIF Summit Entertainment "There was TOO MUCH buttcrack," Pattinson said. "That was one thing I was told they had to cut out, but they didn't cut the shot — they just cut my crack out. Like, they painted over it, because you can show cheek, but you cannot show crack." 8. Julia Roberts was so nervous about filming her sex scenes in Pretty Woman, she LITERALLY broke out in hives. Tap to play or pause GIF Tap to play or pause GIF Buena Vista Pictures “I had never done this kind of stuff before, and I was really nervous," Roberts said. "I'd get hives. They'd say, ‘kiss,’ and I'd get a hive...but the funny thing is that we’d become such a family. This particular crew, we became so close to one another that by the time a scene like this came up — everyone knowing the way that I felt and my kind of value ideas about it — everybody was more nervous than I was.” 9. Mark Wahlberg's first prosthetic penis for Boogie Nights was way too long, so they "embarrassingly" had to remake a second, shorter one...which Wahlberg kept. Tap to play or pause GIF Tap to play or pause GIF New Line Cinema "The first time they made it, they used the exact same specs as John Holmes...a very famous porn star from the '70s," Wahlberg said. "So this thing was down past my knees. Everybody thought it was ridiculous, and I had to come out on the set to show it to everybody. It was very embarrassing, BUT the shorter one they remade is still the only prop I've ever kept from a movie." 10. Keira Knightley needed SEVERAL backup versions of her famous green dress in Atonement, because the dress kept ripping during the library sex scene. Tap to play or pause GIF Tap to play or pause GIF Focus Features "I probably broke them ALL," Knightley said. "You can't have a sex scene in a dress like that! It was all laser-cut in the front, so literally if you touched it [it ripped]. They had so many [backups], and the tops had to keep being resewn and redone." 11. Director John Turturro thought that Kate Winslet and James Gandolfini seemed too tense during their sex scene in Romance & Cigarettes, so he replaced Gandolfini with a "big bouncy ball." Tap to play or pause GIF Tap to play or pause GIF Sony Pictures Classics "One time, I directed a sex scene for a movie, and I realized they seemed too inhibited," Turturro said. "So I decided to take James out of the scene and I put Kate on a big bouncy ball and just had her bounce and look around. The problem was how to connect them so when it was James' turn, he pretended to have sex and I threw Kate's wig around...so if you watch the scene, they're completely free, but they're not in the same room together." 12. Ben Affleck tried to simultaneously direct a sex montage WHILE acting in it for Live By Night, but never yelled "cut," which confused Sienna Miller into breaking character. Tap to play or pause GIF Tap to play or pause GIF Warner Bros. Pictures "You do scenes and, sometimes, I like to go over and over again without cutting, because I don't like to interrupt the flow," Affleck said. "But we had these montages of sex scenes and — in my mind — I was thinking, Well, we're just going again, like without yelling 'cut'; we'll just keep going. And finally, Sienna just started laughing and said, 'Who do you think you are? How many times can one man climax?!'" 13. And finally, Olivia Colman accidentally scared Emma Stone with a wet sponge during their sexy scene in The Favourite. Tap to play or pause GIF Tap to play or pause GIF Fox Searchlight Pictures "So...Emma had to finger me. She was a little bit worried, since it was under the sheets," Colman said. "So I went to makeup and I got a sponge...a big, wet sponge. I put it there as a barrier and told her not to worry about it. So when we were shooting, she was going up my leg and then went 'OH?! [in disgust]' and I was like "Oh no, it's a sponge!"