Katy Perry and John Mayer had a dinner date at Pearl restaurant last night in NYC. After the meal, they headed out to a nightclub together. Katy wore a sexy, sheer dress that showed off her legs for the evening out with her on-again-off-again beau. It was the end of a busy weekend for Katy, who took the stage Saturday at the Night of Too Many Stars benefit for a memorable performance with a young autistic fan in NYC. Her charitable performance followed another fundraising event on the West Coast. On Thursday, Katy linked up with Kate Hudson at the star-studded amfAR Inspiration Gala in LA.