Delevingne, 23, emerged from her home in Kensington, west London last week, brandishing a water pistol and started firing at the photographers, reported Independent online.
Grinning and laughing with her musician girlfriend, the pair ran down the street shooting the pistols. They later attended a star-studded Christmas party at the home of Mick Jagger in the capital.
The couple have been dating for more than a year, but their romance was confirmed when they were seen leaving the BRIT Awards together back in March.