Speculation has been rife that while in Barbados, Simon, 54, and his pregnant girlfriend Lauren, 36, will tie the knot after reports emerged that the music mogul bought an engagement ring and drafted a pre-nuptial agreement before setting off on the holiday.
"We've heard Simon has arranged some sort of ceremony," said a guest at the resort. " It's all so secretive that everyone could be caught on the hop by a surprise wedding."
Simon's former flame Sinitta added fuel to the rumours on unday when she tweeted that she was about to attend a "very special party in Barbados".
Comments from the buisnessman's ex that it might be "rude to wear white" to the special party sent the rumour mill into overdrive that Simon and mother-of-one Lauren are holding their wedding, although she claimed she was referring to another party on the Caribbean island.
Very Special Party today in Barbados - what to wear? .. Would it be rude to wear WHiTE ... Bikini? Hmmmmm— Sinitta 19 (@sinittaofficial) December 29, 2013
On Friday the couple were the picture of contentment as they paced the white sandy shore before father-to-be Simon made a beeline for a cute little toddler he spotted on the beach.
As Lauren looked on with a smile, the man who once completely ruled out having kids, saying: "I'd go nuts", asked if he could hold the baby.
At one point the X Factor boss also bought some art from a man selling pictures on the beach before posing for photos with Lauren with some fellow holiday makers who asked for a snap.
Lauren dressed her blossoming bump in a flattering black strapless swimsuit – which she accessorised with a matching sarong. And like her partner she wore a pair of aviator glasses to shield her eyes from the Caribbean sun.