The One Direction boys are known for their pranks, but when Zayn Malik accidentally takes one too far, Louis Tomlinson's reaction captured on a Vine video is just too great not to share.

At a recent One Direction concert on the US leg of their "Take Me Home" tour, a fan got too excited and threw her mobile phone onstage, UnrealityTV.com writes. She reportedly was hoping that one of the boys would record a message on the phone for her.

Zayn picked up the phone off the stage and threw it back into the audience, but the Bradford boy apparently doesn't know his own strength. The mobile phone reportedly hit the poor girl in the face, and Louis reacts in horror.

A Vine video captured and posted by 1D Professionals on Twitter shows the incident and Louis' expression, UnrealityTV.com reports. The video is captioned: "#VINE Zayn threw a fan's phone back to her and it hit her in the face! Look at his and Louis' reactions!"

We hope the fan is okay!

Watch the hilarious video here: