Late BEATLE John Lennon reportedly conducted an illicit affair with a British singer behind his first wife CYNTHIA's back. Lennon allegedly fell for the charms of star ALMA COGAN in the early 1960s, after performing together on British show, SUNDAY NIGHT AT THE LONDON PALLADIUM. Alma's sister, SANDRA CARON, says, "I knew about Alma and John, of course, but it was something no one admitted because John was married. "We had a very strict Jewish upbringing and my mother would never have approved of a relationship with a married man."