Grown up “Harry Potter” star Daniel Radcliffe and his reported girlfriend Erin Darke were cautious about being photographed together at the premiere of their new film “Kill Your Darlings” on Monday. But a spy said they seemed very much together at the Cinema Society event.

Keeping a safe distance in the public eye, the couple posed for a group shot on the red carpet with director John Krokidas between them. But a source close to the film at the Tao Downtown bash after the premiere called Darke, “Radcliffe’s secret girlfriend.”

The two had been seen kissing earlier this year at their film’s Sundance premiere, but have kept a low profile since.

In the movie, Radcliffe plays poet Allan Ginsberg and has nude love scenes with his male co-star Dane DeHaan.

Also at the Tao bash were Jack Huston, Patrick Wilson, Marisa Tomei, Zach Quinto, James Marsden, Parker Posey and Dree Hemingway. Johnston & Murphy sponsored the shindig.