Picture: YouTube screenshot

Ever watched a prank within a prank? It's a complicated affair, but get it right and the payoffs are epic.

British YouTuber JMX, who gained popularity with his FIFA game videos, has over 2 million YouTube subscribers. So what his girlfriend did was decide to prank him live on his YouTube channel.

What she didn't know is that the joke was on her. She approaches him with a pregnancy test with a positive result. Her reason behind it: "He's being a knob, so I'm going to do it to him."

His response is epic and things seem to get out of control when he proceeds to call his father. Eventually she's forced to come clean.

READ: Prince Harry ‘is the coolest’, says Margot after prank call

Have you ever played a prank and someone and it backfired? How far would you go with a joke before realising it's gone too far?