Conversation so far:
What are some of Pamela Harriman's romantic involvements?
Pamela Harriman had romantic involvements with men such as: W. Averell Harriman, who much later became her third husband; Edward R. Murrow; and John Hay Jock Whitney.
How many times was Pamela Harriman married?
Pamela Harriman was married three different times.

Question: Why did she keep getting divorced?
Self-contained rewrite: Why did Pamela Harriman keep getting divorced?