The 36-year-old socialite - who is now estranged from her businessman husband Andrew - is expecting a child with the media mogul and hid her affair by telling her spouse she was seeing her parent.
According to reports in the New York Post, Lauren pretended she was going from her home in New York City to Miami, Florida, to visit Carole Saland.
The couple - who were friends with the 'X Factor' boss for more than six years - also have a seven-year-old son Adam.
Andrew filed for divorce last month, naming Simon, 53, as co-respondent in the papers and citing adultery as the reason for the failure of his marriage.
Simon is trying to get his name removed from the papers and is said to remain ''hopeful'' he will not be made to face court.
Carole has also spoken out to defend her daughter from critics, claiming her relationship with Andrew was not ''made in heaven''.
She previously said: ''Lauren isn't a gold-digger. She's a nice girl from Miami Beach.
''Her marriage was not a marriage made in heaven and life goes on, people go on.''
The long-awaited fourth season of 'Peaky Blinders' debuts later this year, with Tom Hardy now confirmed to reprise his role as Alfie Solomons.
For the sci-fi horror thriller Life, Jake Gyllenhaal and Ryan Reynolds team up to play astronauts trying to contain an aggressive alien creature.
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