Simon Cowell’s my brother-in-law – he insulted me first time we met & was anti-marriage but now I fear he’s a groomzilla

KNOWN as TV’s Mr Nasty and an eternal bachelor, Simon Cowell surprised everyone when he revealed he was getting married – including his sister-in-law Emma Cowell.

The author, 45, who's married to Simon 's older half-brother Tony, 70, never thought the Britain’s Got Talent judge, 62, would settle down – but admits his fiancée Lauren Silverman , 44, has “changed his life”.

In an exclusive interview with The Sun, Emma said she’s witnessed “a complete transformation” in her brother-in-law – who dealt her one of his trademark insults on their first encounter.

Though Emma, whose debut novel One Last Letter From Greece is out next month, did reveal her bossy brother in-law may be a little overbearing when it comes to the wedding planning.

She told The Sun: "Will he be a groomzilla? It's hard to say. Simon has very clear likes and dislikes.

"He is used to calling the shots on TV and behind the scenes so I'm sure he applies that to all areas of his life, including his wedding.

"But Lauren will have equally strong ideas as it's her big day too. It's also important for Eric and Simon's stepson Adam.

"I'm sure he's got lots of ideas, plans, and maybe a few surprises for Lauren, but I imagine it will be a low-key, really special day for them.

"None of us thought this day would come! Simon was a bachelor who never wanted to get married, engaged or be a dad, but look at him now."

While Emma knows her brother-in-law as an "incredibly kind, generous and a wonderful father" today, when they first met 15 years ago he didn't leave such a good impression.

She recalled: "When I first met him, I made brownies and he criticised them.

"He suggested they needed buttercream – but they didn't because that would make them a cake in my opinion. I'm not sure if anyone won that argument.

"Simon was wrongly seen as Mr Nasty or Mr Mean for a long time but he's had a lot of things happen in his personal life and has always been honest and told the truth."

The Britain's Got Talent judge is a "self-made man" who first found success in the 80s and 90s as a record producer, talent scout and music industry consultant.

In 2001 he kickstarted a lucrative TV career after co-creating and appearing on Pop Idol , which contributed to his reported £486million fortune today.

The ITV show's success led onto other formats, including The X Factor , many of which were syndicated worldwide and the winning acts signed to his entertainment company Syco .

But before Simon's superstardom, Simon's first mentor was his older half-brother Tony, who reportedly bought him his first-ever record – She Loves You by The Beatles.

Emma, who married Tony in 2014, said: "There are a lot of stories about their naughty behaviour but they have always respected each other.

"Tony was always a huge music fan and would play The Beatles and Eagles over and over again, and Simon was certainly influenced by that."

Nowadays it appears the brothers don't always agree on music tastes.

Emma recalled: "I texted Simon to say Tony was going to make me listen to Leonard Cohen for the first time and he replied, 'Leave! Run for the hills!'

"While it wasn't love at first listen, I'm completely obsessed now. The Cowell brothers grew up during a fantastic time for music, it was rich pickings.

Simon was wrongly seen as Mr Nasty or Mr Mean for a long time but he's had a lot of things happen in his personal life and has always been honest and told the truth

Emma Cowell

"They lived in a very musical household, their late mother Julie was always playing Frank Sinatra and they all still have huge love for bandstand numbers."

Simon’s love of The Beatles was highlighted to Emma when Sir Paul McCartney played on one of The X Factor live shows.

"After the programme finished, Simon, Tony and I went back to his house to watch the performance again," Emma recalled.

"All three of us were in absolute awe seeing Paul McCartney sing and it was a very special moment.

"Simon couldn't believe we had seen one of The Beatles live. I guess you're never too famous to be starstruck."

Reformed workaholic

Emma has witnessed the change in Simon after he started dating New York socialite Lauren in 2013 – but it wasn't a smooth start to their relationship.

They got together while she was still married to his good friend, real estate mogul Andrew Silverman.

The couple welcomed their son Eric in 2014, and on New Year's Eve last year, Simon popped the question.

Emma said she saw a big change in Simon when he discovered he was going to be a father.

"When Lauren was pregnant that was all he could talk about in the South of France. He showed us a baby scan and was so excited," she recalled.

"He kept asking us to guess what the gender was, and since Eric was born his priorities have completely changed.

"It wasn't something he ever expected or planned but it blew his world apart in the best way possible. While work is important to him, Eric and Lauren come first above all else."

Since Eric was born, Simon’s priorities have completely changed. It wasn't something he ever expected or planned but it blew his world apart in the best way possible

Emma Cowell

Before Simon met "the love of his life", Emma claims he was a "workaholic" whose job was "his hobby, his life and all-consuming".

Now he's unrecognisable from the man she met 15 years ago, as his "priorities have shifted beyond measure".

Emma said: "Becoming a father definitely changed him – if anything it's made him sillier. His sense of humour is very silly and ridiculous.

"The last time we met a few months ago we were playing a game, but Simon and Tony weren't abiding by the rules, they were putting rude words in sentences and being funny.

"Simon's definitely dafter now and loves to make Eric laugh, it's really infectious and lovely to see. We are incredibly proud of him."

Supportive

Emma says Simon was incredibly supportive when she took time out to write her first book, which she penned during lockdown to honour her late mum, who died aged 59 in 2012.

She also channelled her own "really unsettling" life experiences, which include fertility struggles, a heartbreaking miscarriage and an ordeal with a stalker who threatened her with violence while she worked as a BBC radio presenter.

Her novel has received high praise from fellow writers and popstar Peter Andre, who called it "a beauty".

Emma said: "Writing my novel is something I never thought I'd do, but Simon was incredible and was jumping for joy when I got a publishing deal.

"He asked for a free advanced copy, but I've told him he'll have to go to a book shop like everyone else when it comes out in June.

"I'm very privileged to know Simon away from the cameras and for him to be patron of my charity – Together For Short Lives .

"He donates a lot of his time to meet children with life-limiting conditions and makes magical memories for them and their families during heartbreaking times.

"Simon spends hours talking to parents and playing around with the kids being silly.

“It chokes me up when I think about it but I'm so proud that he is part of our family."

Emma Cowell's debut novel One Last Letter from Greece is available in book stores and online from June 9 – click here to pre-order today .