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, 21, has dated and broken up with 34-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, but as far as we know the pair are back on again. They even had to dodge an engagement rumor in February 2014!