Credit: Twitter/badgalriri.

If this isn't proof that Rihanna and Chris Brown are back on, we don't know what is. Rihanna posted a photo of her kissing Brown's head on Instagram Thursday night, her body wrapped around his. "I don't wanna leave!!! Killed it tonight baby!!!" she wrote, likely referring to Brown's Thursday concert in Frankfurt, Germany.

The two celebrated Thanksgiving in Berlin and shared a variety of semi-clothed snapshots of each other last weekend. Rihanna tweeted a shirtless photo of Brown, followed by her own topless photo.

PHOTOS: Chris Brown and Rihanna Heat Up

In an interview with Power 106 radio host Big Boy earlier this month, Brown said he and Rihanna are "working on their friendship."

He elaborated, although not eloquently: "As far as our personal life, I think people just got to give it a chance - or not even give it a chance, but shut the hell up. It's me. At the end of the day, whatever opinion they have ain't going to change nothing I'm doing."

Rihanna's adopted a similar attitude. She brushed off the "obsession" about her and Brown in a recent interview with Vogue, saying "The world hasn't let go. They haven't seen any progress in our friendship, because they don't see anything."

Rihanna and Brown split in 2009 following his brutal assault on her.