A mother-of-three was left feeling physically ill after a prank ruined their meal in Jimmy's Restaurant at the O2.
Jade Miller was dining with her three sons at the all-you-can-eat grill when they caught sight of graphic gay sex on the restaurant's booking screen.
The monitor had been switched to Meatspin, a popular prank site which shows a man spinning his penis around while being penetrated by another man to the sound of Dead or Alive's "You Spin Me Round (Like A Record)".
Mrs Miller told the News Shopper: "Just as we were leaving the boys said to me 'there's something bad on the computer mummy'.
"I went over and had a look and there was gay porn on the screen and the kids were standing there laughing their heads off. I don't think they understood what was going on.
"Long story short, there was gay porn, two men having sex and my children witnessed all of this.
"I'm in such shock, what do you say to a six-year-old and a nine-year-old when they've just seen porn?"
Staff attempted to turn the screen off, but Miller demanded it be left on for the police.
When officers arrived, they informed the 27-year-old there was nothing they could do except turn it off.
"Officers believe, at this stage, that the material shown was the result of a pop-up which had been received via the restaurant's email booking system," a Met Police spokesperson said.
"Officers spoke with the restaurant's manager and provided advice around computer security and spam management."
This isn't the first time this website has been seen in public. In 2013 a computer engineering student was arrested for hacking his university's WiFi and forcing every user connected to the internet to view the shock site.