Published Thursday, 27 March 2014
Nigel Harman stars as the Simon Cowell-like character in musical I Can't Sing! (© Getty)
The music mogul - who became a first time dad in February - said being at the show's opening night was like seeing his "second baby born this year".
Walking the red carpet with girlfriend Lauren Silverman in London, he said: "It's exciting, and I never thought I'd be in this spot. I don't know much about the West End or musicals but the very first time I saw the run through I really, really liked the show.
"And now I've seen the Twitter reaction to the previews and the people who've seen it really love it. So I'm thrilled."
The new musical, which takes an "affectionate poke" at the X Factor, stars former EastEnders and Downton Abbey actor Nigel Harman as the Simon-like show boss.
The productions also boasted characters with striking resemblances to Cheryl Cole and Louis Walsh, while singer Gary Barlow gets a nod with a dog named after him.
Cowell admitted: "It's embarrassing, but I've got a thick skin."
The new show has suffered early production problem during its preview performances, with reports the first night was hit by a 50-minute interval.
Producers are now understood to have got the delays under control.
Cowell said: "It's a big production, that's why you have all the previews and you work everything out. But it worked out fine in the end."
I Can't Sing! writer Harry Hill said he was confident about opening night, insisting: "I feel excited more than nervous."
"We've run it now for four weeks and it's always gone really well, so, the law of averages..."
And he also promised he hadn't held back when mocking Simon or any of the other judges, adding: "We never thought twice about it. We wrote what we wanted to write and he was always fine about. I'm not the sort of person who is nasty for the sake of being nasty."
The opening night of the much anticipate musical was attended by a number of famous faces, including Louis Walsh, Sinitta, former X Factor stars Rylan Clark and Stacey Solomon and Britain's Got Talent judge Amanda Holden.
© UTV News