Surprise BFF Alert: Robert Pattinson and Katy Perry

Rob Pattinson and Katy Perry were party pals last night, enjoying a night of karaoke at Dimples Supper Club for a mutual friend's birthday. 

RadarOnline.com reports that the stars were spied close in conversation, at one point touching foreheads and giggling.

While Katy — who recently introduced boyfriend Russell Brand to her parents — took to the stage to belt out a karaoke number, the New Moon star stayed low key sipping whiskey and cokes, and taking numerous cigarette breaks.