Prankster under fire for pretending to blow up son

A US comedian has divided social media after appearing to blow up his toddler son in a bike explosion in a prank that reduced his girlfriend to tears.

Video shows YouTube prankster Roman Atwood seemingly mulling over buying a quad bike, with his three-year-old son Kane strapped behind the wheel, when he convinces his girlfriend Brittney to grab a chequebook to seal the deal.

With her back turned, and his son remarkably compliant, Atwood quickly puts a dummy child in his son's place before she returns.

The quad bike then takes off, with the parents screaming and giving chase, before going over a jump and exploding, Hollywood style.

His girlfriend becomes wise to the prank only seconds after the explosion, obviously painfully aware of her boyfriend's twisted sense of humour.

"It is not funny," she says, aiming a kick at Atwood.

"It's kinda funny," Atwood sheepishly replies.

"Don't touch me, I'm done, I can't do it," she says through tears, before hugging Kane.

The video has been viewed more than 3.5 million times since being uploaded to YouTube on Sunday, and unsurprisingly has polarised opinions.

"Such a jerk husband. Britney shouldn't have to go through this," user Leavwix said.

"This video was so funny I spat out my drink now," Duran Anderson said.

Atwood's YouTube channel has more than seven million subscribers.