Samantha Giles digs her fingernails into her hands to stop herself from spoiling "Emmerdale" scenes by laughing.
The 47-year-old actress" co-star Jonny McPherson - who plays Doctor Jonathan Boam - has also taken on the tactic to stop himself from cracking up during filming, and he has been left with "bruised palms" as a result.
Speaking about shooting scenes with Samantha (Bernice Blackstock), he said: "It would be easier to count the ones where we have kept a straight face.
"Once Sam has gone, that's it. She has a tactic of digging her fingernails into the palm of her hand to stop her from laughing, which I've adopted.
"I have bruised palms by the end of a scene. She's a terrible influence."
Jonny insists he and Sam are "never" awkward when they are filming intimate scenes because they are "good friends".
He added to Inside Soap magazine: "On the first day of a new job you might have to kiss someone, and it can be very peculiar situation to stick yourself in.
"But Sam and I are good friends, and we're really comfortable with each other."
And Sam and Jonny aren't the only soap stars who inflict pain on themselves to stop cracking up in a scene.
"Coronation Street" actor Simon Gregson - who plays Steve McDonald on the ITV soap - recently revealed his co-star Ben Price (Nick Tilsley) has to stab himself with a toothpick to stop himself laughing.
He said: "I love working with Chris Gascoyne and Ben Price, before now Ben has had to have a toothpick to stick in his hand to stop him laughing in a scene."