Warren Beatty and Joan Collins attend a part…

Warren Beatty and Joan Collins attend a party in Los Angeles, circa 1959. 

In 1959, Collins began a relationship with Hollywood newbie Warren Beatty:

“Although I wasn’t madly in love with Warren, he and I were actually very compatible, even if he needed to have sex several times a day, which often wore me out. I once shocked my friend Joanne Woodward — who was married to Paul Newman — by saying I needed a break because the endless bonking was exhausting me. ‘Don’t!’ she warned. ‘If you have a relationship with a libidinous 22-year-old, you’d better let him. Otherwise he’ll look for other avenues, as it were.’”

The couple continued seeing one another and eventually became engaged, but

Beatty’s womanizing led to their split.

(Source)