Justin Bieber's facial expression pretty much spells "SCARED TO DEATH."

By now, Justin Bieber MUST be used to getting pawed at on the regular by his gazillions of fans, but that doesn't mean he always has to like it! We reallly can't blame the guy for looking INCREDIBLY uncomfortable while getting an unsolicited kiss from a particularly eager Belieber in London. Where's that girl gonna be when Justin has to explain the lipstick marks to his boo Selena Gomez?! J/K! But really, Justin's "YOU'RE IN MY PERSONAL BUBBLE!" face pretty much screams plain fear.

The "Beautiful" singer's reaction may also explain why he likes to fly on his own private jet -- because god help us all if this kind of Bieber-induced mayhem gets unleashed on an enclosed commercial airplane thousands of feet into the sky. Or maybe Justin's reaction was just him feeling tired from promoting his new book, "Just Getting Started," while across the pond? ORRR it could be that GIGANTIC mob of screaming human fans. We're only specifying by species 'cause Justin seems to have no problem getting surprise kisses from adoring monkey fans.

Photo credit: Fame/Flynet