May-December Relationships

Sean Penn, 50 & Scarlett Johansson, 26 The odd pair began dating this past January, and Scarlett has reportedly moved in with him. In Dec. the "Iron Man" star abruptly ended her two year marriage to Ryan Reynolds. While Sean's 13-year marriage to Robin Wright Penn ended in Aug. 2009.

Charlie Sheen, 45 & Rachel Oberlin and Natalie Kenly, 24 Age is the last thing that stands out when you see these three together and hear about their seemingly amicable - albeit completely bizarre - "arrangement" Charlie's ex-wife, Denise Richards is only five years younger than the former "Two and a Half Men" star. While his most current ex, Brooke Mueller, is 12 years his junior. They just keep getting younger for Charlie. Winning... (AP) (AARON VINCENT ELKAIM)

Michael Douglas, 66 & Catherine Zeta-Jones, 41 The couple, who has been married since 2000, appear to be stronger than ever now that Michael's throat cancer is in remission and Catherine has sought treatment for a bipolar disorder. They always seem to truly be there for one another. (AP)

Harrison Ford, 68 & Calista Flockhart, 46 The 22-year age gap didn't deter the "Brothers & Sisters" star from dating "Indiana Jones." After a seven year courtship the pair finally wed in 2010. (AP)

Demi Moore, 48 & Ashton Kutcher, 33 When this unlikely pair first got together in 2003, fans were skeptical as to whether they were serious or it was one of his many pranks. But two years later they tied the knot and are still going strong. Demi recently explained how they keep their marriage alive. "You have to make your relationship a priority," she says. "I think we spend very little time apart." The couple also revealed that they leave each other little love notes in the form of post-its around the house. "My most recent one was just a reminder that I was magical," says the actress. How sweet. (AP)

Kelsey Grammer, 56 & Kayte Walsh, 29 The "Frasier" star was barely divorced to his wife Camille, 42, before he married Kayte on Feb. 25. This is Kelsey's fourth marriage. For more pics of your favorite stars, go to <a href="http://www.x17online.com" target="_blank">x17online.com.</a> (X17online.com)

Eva Longoria, 36 & Eduardo Cruz, 26 The "Desperate Housewives" star began dating Penelope Cruz's younger brother just months after her divorce from Tony Parker. The pair have been spotted making out all around Los Angeles. It's no surprise that Eva found herself a younger man. Her ex-hubby is 28. For more pics of your favorite stars, go to <a href="http://www.x17online.com" target="_blank">x17online.com.</a> (X17online.com)

Rod Stewart, 66 & Penny Lancaster, 40 Rock stars and younger women go hand in hand. The couple, who has been married since 2007, have two kids together. Rod has been married three times and has a total of eight kids with different women. Wowza. (Reuters)

Howard Stern, 57 & Beth Ostrosky, 38 The radio host has met his fair share of gorgeous models over the years, so it's only right that he's married to one. The pair began dating in 2000 and were married seven years later. (AP)

Benicio del Toro, 44 & Kimberly Stewart, 31 Okay, so these two are "not a couple," but they were together long enough for them to be expecting their first child together this year. Interesting. (Reuters)

Hugh Hefner, 100 & Crystal Harris, 24 Okay, so he's not really 100 - he's 85 - but that's still more than triple Crystal's age. At what point does the age gap stop being cool and start being gross? (AP)