After several years of on-and-off dating, it looks like Demi Lovato and Wilmer Valderrama are rekindling their relationship again.

According to Us Weekly, the duo, who initially became a couple in 2010 and then broke up and got back together several times, spent Valentine's Day together, first sharing a romantic meal earlier in the day and then reportedly "making out" at the grand opening of Topshop and Topman's L.A. store later that night.

Well, clearly chemistry is not the problem with these two...so what is? There has to be a reason they are constantly splitting and then getting back together. At 33 years old, Valderrama is significantly older than 20-year-old Lovato. So maybe it's the age difference? Or are they just trying to rival Selena Gomez and the Biebs for the most kinda-sorta- breakups EVER? I've lost exact count, but at this point, I'm pretty sure this will be the 3rd or 4th reunion. I guess they simply can't stay away from each other!

Still, like I said, it's not like Lovato and Valderrama are the only ones to repeatedly break up and get back together. Below, check out a few more of Hollywood's notoriously on-again, off-again couples!

Image via Splash News