Demi Lovato and Wilmer Valderrama: 13 Years
It seems like just yesterday that Demi Lovato was a teen star on a Disney sitcom. However, gone are the days of dating Joe Jonas types — the X Factor judge, 20, has dated and broken up with 33-year-old actor Wilmer Valderrama twice. After first dating in 2010, they attempted to rekindle the flame in late 2011.
Unfortunately, it didn't stick that time, either.