Sinatra and Gardner
Ava Gardner met Frank Sinatra in 1943. They started dating in 1949 while he was still married to his first wife. They officially tied the knot in 1951. They had a crazy, tumultuous relationship that involved sinful shenanigans and illegal substances.
Gardner said that everyone in her life advised her against marrying Sinatra. Even Sinatra's ex-partners told her she should just run. She didn't, and they were married for six years before filing for divorce. They separated multiple times and cheated on each other constantly. Somehow, the two stayed close friends until Gardner's death.