Cameron Diaz with brown hairCameron Diaz has found there are advantages to having a widely publicised relationship - your fans keep an eye on your boyfriend for you.

Two fans of famously blonde Cameron spotted her long term boyfriend Justin Timberlake kissing a brunette girl in Forbidden City nightclub in Hollywood and one of the onlookers couldn’t help but to tell him off, saying: “What are you doing? You’re cheating on Cameron!”

But the brunette turned out to be Cameron herself, having dyed her hair for a new movie. She reportedly thanked the girls for being so protective of her then told Justin that he should know “my girls are always watching”.