Robert Pattinson and Kristen Stewart showed everyone that Robsten is still going strong when they stepped out on the town together last night, and they were joined by Pattinson’s good friend Katy Perry. In fact, the three superstars were out for a birthday dinner for the Perry’s assistant, Tamra Natisin. In this very short (6 seconds to be exact) video that’s made its way online, Perry, presents her with a chocolate birthday cake to Natisin while Stewart gets up in her chair to snap a photo of Pattinson while the whole table sings “Happy Birthday.”