Rihanna's birthday throwdown on Monday had a pretty nice A-List lineup with new bestie Katy Perry, Bruno Mars and Chris Martin all in attendance... as well as Rihannas ex, Chris Brown. Rumors are spreading that he even sat next to the birthday girl herself!

Brown was reportedly trying his best to keep the appearence at the party a secret, he actually tried to FORCE all the employees of the famous Hearst Mansion in Beverly Hills to sign confidentiality agreements. Chris refused to enter until everyone signed a Nondisclosure agreement or NDA.

Chris eventually made his way in the party, and spent a most of the night with Rihanna. According to many people who attended the gathering, the two got real lovey dovey sitting next to each other and holding hands. I was one of the first to lay into Chris Brown for putting a hand on any woman. Now I have to question how much of this whole mess is even true, seeing as how he is allowed to be there with a restraining order... and that she even wants him there.  Also, Rihanna's cake was a giant spliff, for those who don't know what that is, keep it that way. Even had a icing figure of Rihanna riding it like a horse. ROLE MODEL!