Today's news you might've missed:

• The world is now pretty much able to spot Rihanna's breasts in a lineup thanks to her 1) new tattoo and 2) her sharing a photo of said tattoo on her Twitter account. [Rihanna's Twitter]

• Meanwhile, Rihanna's bestie Katy Perry seems to be offering more proof that she's dating John Mayer with a sighting at a Las Vegas strip club over the weekend. They could be pals, though - we know of guy and girl friends who enjoy going out for the occasional lap dance. So we hear. [People]
• James Cameron's idea for a fourth "Avatar" film: "[B]asically it goes back to the early expeditions of Pandora, and kind of what went wrong with the humans and the Na'vi and what that was like to be an explorer and living in that world."[MTV]
• On September 15, "Saturday Night Live" will ring in the new season with three new faces: Cecily Strong, Aidy Bryant, and Tim Robinson have joined the sketch comedy show. We see you trying to fill the Kristen Wiig, Andy Samberg and Abby Elliott-sized hole in our hearts, NBC. [NYT]

• She couldn't ask him to "Call [Her], Maybe" forever: Carly Rae Jepsen's moved on with her next single, "This Kiss."