Of Human Bondage (1964)
starring Laurence Harvey, Kim Stanley, Robert Morley, Siobhan McKenna, Nanette Newman, Ronald Lacey
IMDb synopsis:
Medical student Philip fall in love with Mildred, a waitress. Although she is a flirt, they have a love affair. When Philip is told about her constant infidelity, they break up. Mildred quits her job and becomes a prostitute, but Philip is still in love with her. Based on the novel by W. Somerset Maugham
The version with Leslie Howard and Bette Davis (1934) is better-known and more-frequently shown.
NOTE: I seem to have a troll following me around, thumbs downing every answer I give. This iS the correct answer, in spite of the thumbs down.
