Simon Cowell is believed to have hired a yoga teacher for pregnant girlfriend Lauren Silverman. The X Factor chief is keen for the 36-year-old American socialite to stay calm through her ongoing divorce.

Lauren is being divorced by her husband, real estate tycoon Andrew Silverman, who has named 53-year-old Cowell in his at-fault divorce filing.

The Mirror quotes a source close to Lauren as saying: "One of her friends suggested a particular yoga specialist and Simon thought it was a great idea so he got her on board."

And another source has told US Weekly that the relationship between Cowell and Lauren is nearly four years old.

"Lauren has loved Simon forever. And they started having an affair four years ago. The relationship began as a fling, but the baby - due in February - changed everything. Simon and Lauren are together. They talk 100 times a day."

Lauren is already mother to one child - seven-year-old Adam Silverman.

According to US Weekly's report, the initial meetings between Lauren and Cowell were hushed. But by January it was clear that they saw a future together and she even began consulting divorce lawyers.

Meanwhile, Cowell's plans for a luxury yacht cruise trip to St Tropez continue. The Mail Online reports staff members on the 196.9ft long chartered boat were practising fire drills ahead of the month-long journey.

Lauren will not be on board though. The mother-to-be is expected to rest at her home in the Hamptons, New York. But ex-girlfriends Sinitta, Jackie St Clair and ex-fiancée Mezghan Hussainy are expected to accompany Cowell.