Los Angeles, March 23 - "Twilight" co-stars and real life lovers Robert Pattinson and Kristen Stewart were spotted dining out with Katy Perry to celebrate the singer's assistant's birthday.

In a short video posted on YouTube, Stewart, who is good friends with the birthday girl Tamra Natisin, was seen standing next to Pattinson, while Perry placed the cake and started singing "Happy Birthday", reports femalefirst. co. uk.

Perry seemed to be in a good mood considering she has just split with boyfriend John Mayer after a seven month romance.

The "Twilight" actors, who briefly split last summer after Stewart was caught cheating with married film director Rupert Sanders, have been making the most of their time together by hitting the town for outings.

News of the pair's reunion became public Tuesday at a karaoke bar in Los Angeles, and a lucky fan even managed to get a photo with the duo. (IANS)