Jake Wood said Cheryl caught the giggles while performing 2:22 A Ghost Story in the West End, with the pair “getting in trouble for laughing quite regularly”.
The former EastEnders actor, 50, stepped in to reprise his role as Ben in the supernatural thriller after People Just Do Nothing’s Hugo Chegwin had to withdraw from the show due to illness during rehearsals.
Wood originally starred alongside singer Lily Allen – in her West End debut – as well as Silent House actress Julia Chan and West End actor Hadley Fraser in the production.
Singer-songwriter Cheryl took over from TV presenter Laura Whitmore when she joined the new cast for the show, which is running at the Lyric Theatre until April 23, featuring Horrible Histories actress Louise Ford as Lauren and theatre star Scott Karim as Sam.
Cheryl, who has dropped her previous surnames of Tweedy, Cole and Fernandez-Versini, is making her West End debut as Jenny.
Appearing on Good Morning Britain, Wood was probed over his “mischievous” behaviour on stage a few nights ago, causing the 39-year-old Girls Aloud singer to “corpse” on-stage.
He said: “It’s all sort of new to Cheryl, she didn’t know what corpsing was – corpsing is when you laugh on stage. We’re getting in trouble for laughing quite regularly.
“It’s part of the show and the characters – although it’s very scary, there are very sort of funny moments, so it’s just trying to stay in the moment. When the audience are enjoying it, it’s difficult to keep a straight face.
“You catch someone’s eye and you just know someone’s about to go. You can’t look at them again for the next sort of five minutes.”
He said that Cheryl, who has been acting for a total of four weeks, has had “amazing reviews” and is “incredible”.
Wood, who is best known for playing Max Branning in the soap EastEnders, did not rule out a return to the much-loved BBC show.
He said: “I felt quite lucky when I joined EastEnders, I was 33 when I joined and I’ve been acting professionally since 10 years old, so I’ve got quite a lot of experience before I joined, so I felt lucky for that.
“They’ve kept the door open. I don’t think at the moment, but never say never. You know an actor’s life is normally different jobs and different characters and I’m enjoying that at the moment.”
He also said that training for the TCS London Marathon in honour of EastEnders star Dame Barbara Windsor for dementia research funding while starring in a West End show “is not easy”.
“We did it in 2019 I think with (her husband) Scott and there was a group of us from EastEnders and we’re doing the same again. So hopefully we’ll raise some money and just keep the awareness of Alzheimer’s, dementia – over a million people suffering with Alzheimer’s at the moment in the UK.
“On my days off basically I’m doing the long runs, I did 10 miles on Monday,” he said.
Wood also spoke of his appearance as Rodney Trotter’s assistant in Only Fools And Horses when was he was aged 18.
He added: “Literally this was an afternoon’s work, we’re probably going back over 30 years ago. I still get invited to the conventions, I still get fan mail, just from that – it’s amazing.
“Few hours’ work, a bit of pocket money when you’re 18 – didn’t think any more about it, but obviously it is iconic.”