Just the pair of celebrities you automatically assume will be hanging out together and that you'll see smiling photos of every day, right? Definitely.

Rumer Willis - daughter of Bruce Willis and Demi Moore, stepdaughter of Ashton Kutcher, friend of Lindsay Lohan and Hayden Panettiere - was seen partying it up at the Maroon 5 concert at the Pearl Theater at the Palms in Las Vegas.

Hopefully, Adam Levine didn't try to hit that. You never know, though.

With Rumer Willis is Sara Ramirez, who plays Dr. Callie Torres - the third leg of the worst love triangle ever with George O'Malley (T.R. Knight) and Izzie Stevens (Katherine Heigl) on Grey's Anatomy. Maybe they're friends?

Who the heck knows. Let's just hope there were no pics of a nude Rumer Willis wearing a dunce cap taken later in the night after a few drinks were consumed.