Story By:  Ana Marjanovic, Sub-Editor: Michael Leidig, Agency:  Newsflash

This is the excruciating moment a horrified teacher realises his sexy online chat with his girlfriend has been sent to the classroom smartboard by mistake.

Students at the middle school in the Chinese capital Beijing had been studying quietly while their teacher was viewing his private messages.

But he forgot that his laptop was linked to the class smartboard which meant the students could read everything on his screen.

A hilarious video – recorded on 24th May – shows how the teacher’s girlfriend sent a sexy selfie video asking if her lips looked good when she licked her new lipstick.

He replied that she was beautiful and that he wanted to kiss her.

The teacher – not named in local media – only realised something was wrong when the students began howling with laughter.

As he snapped the screen shut, he buried his head on the table quaking with nervous laughter.

Then when he tried to throw a box of tissues at them, he fell off his chair slipping underneath his desk, causing even more laughter as he tried to unplug the smartboard.