Whilst married to James Dougherty and Norma Jeane is believed to have slept with photographer Andre De Dienes, which he discusses in his book. A letter to De Dienes also confirms a close relationship.
Marilyn is also believed to have been intimate with her agent Johnny Hyde until his death in 1950 and had an affair with Elia Kazan in 1951.
Arthur Miller was still married when he started seeing Marilyn in 1955, although she was single.
She had an affair with Yves Montand during the making of Let’s Make Love when she was married to Arthur Miller and he was married to Simone Signoret.
It is also firmly believed Marilyn slept with President John F Kennedy at Bing Crosby’s home in 1962. He, of course, was married to Jaqueline Kennedy. JFK was a serial adulterer.