In 2011, Demi Lovato secretly dated Ryan Phillippe, a year after she had ended things with Joe Jonas.
Demi only just recently opened up about the relationship in her documentary Simply Complicated, saying, "When I turned 18 we started dating. I think it was love at first sight, we connected on a level that I've never connected with anybody before. He was just my rock, my everything. I'm pretty sure that I'm not going to meet anybody that compares to him, but I'm trying to keep an open heart and open mind when it comes to that."
Now, Ryan was spotted attending Demi's Halloween party, and didn't leave her place until 5am, hours after the rest of the guests had already left.
Maybe they're back on? Maybe it was just a friendly catch up?
We may never know. What we do know is that Demi looked like absolute FIRE in her police costume over the weekend.