The X Factor mogul, 53, and New York socialite Lauren jetted into London this week following a holiday in the French Riviera with friends including Simon's ex-girlfriend Sinitta.
Clearly not tired from their travels, on Wednesday evening (28 August) the parents-to-be dined at Italian restaurant Scalini in Chelsea, where they were seen holding hands and smiling at each other.
Lauren's baby bump was visible in her coral pink dress, while Simon went for his usual off-duty look of jeans and a shirt.
Simon opened up about fatherhood for the first time last week, while attending One Direction's This Is Us movie premiere in London.
He told BBC: "Things are changing in my life right now for the better. I'm proud to be a dad. It's something I haven't thought of before and now I feel good about it."
Simon also described Lauren, 36, as a "very special girl".
Prior to the 1D premiere, the music mogul had declined to comment publicly on the pregnancy claims, which were first reported in July.
Simon's back in the UK ahead of the premiere of the tenth series of X Factor this weekend – but might find time to squeeze in a visit to his mother.
A source told the Daliy Star that while Simon is here to oversee the X Factor launch and carry out some business meetings, "it's entirely plausible that he will want to pop and see his mum and take Lauren along."
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