She attended "The Mortal Instruments: City Of Bones" Los Angeles premiere on Monday wearing a white Cushnie et Ochs cut-out dress. Perhaps being newly single contributed to the sexy ensemble?
The British beauty and her "Mortal Instruments" co-star Jamie Campbell Bower split up earlier this summer after a one-year relationship. She told Us Weekly that filming their love scenes wasn't very exciting. She said: "In terms of kissing, I promise you that it is super awkward and super unsexy because everyone's staring."
The film centers on Clary Fray (Collins), a New York teenager who discovers that she is the descendant of a line of Shadowhunters, a secret group of young half-angel warriors emmeshed in an ancient battle to protect the world from demons.
The film hits theaters on Aug. 21.
Check out more photos of Lily from the premiere...