We all yawn–usually when we're sleepy, or bored. To this day, experts aren't 100% sure why we yawn, but research indicates that yawning might be a way to cool down our brains. While it's a natural thing to do, we tend to cover our mouths when we yawn in public, and so do some celebs... but not always!
In this gallery, we bring you snaps of stars who've been caught yawning in public. Click on for some laughs!