Jealousy is a natural human character trait. Just like loyalty, fear and honesty, there are times when we cannot control how we feel.
Whilst it's good to let it all out and express yourself, there are some times when it's best to keep it all concealed - especially when there are cameras about!
The following people know that only too well after being caught on camera at the precise moment their internal green-eyed monster exposed itself...
1. There is no "love" lost between these two
Andy Murray and Novak Djokovic have a storied rivalry. Both may be tennis legends, but it's the Serbian star who is the reigning champion when they do come face-to-face. With 25 wins out of their 36 games, the 30-year-old Djokovic is often the object of Murray's envious eye - well, except for the Olympics where the 30-year-old British athlete took home two golds, while Djokovic only boasts one bronze in his collection.
2. That's how 'Biology' works
Girls Aloud ruled the world of pop in the noughties with their catchy tunes. When they split in 2009, Cheryl went on to become the stand out star. This caused a lot of bitterness with the four other girls who were understandably jealous of Cheryl's fame. But it would appear that the rivalry between them started much earlier if this photo is anything to go by!
Check out some more people looking particularly green....
3. Eye see what you did there
Looking at another woman whilst with your girlfriend is a punishable and unforgivable offense. Luckily for this guy, his girl spotted the threat before he did and avoided a catastrophe by covering his eyes.