Not long after arriving in Los Angeles, Southern met Gail Gerber, a young Canadian-born actress and dancer, on the MGM backlot. Gerber, who used the stage name Gail Gilmore, was working as a dancer on an Elvis Presley movie, and she had a non-speaking role in "The Loved One". Southern and Gerber soon began an affair. The relationship intensified during July/August 1964, and after Southern's wife and son went back to East Canaan, Southern and Gerber moved in together in a suite at the Chateau Marmont hotel.