Scarlett Johansson
The woman who once claimed that monogamy was unnatural met and married Canadian-born actor Ryan Reynolds in 2008, but the couple announced their plans to divorce in December of 2010. After a whirlwind May-December romance with 50-year-old actor Sean Penn, Johansson is rumored to be back on the singles market. Maybe Scarlett doesn't believe in monogamy after all.
