This is the moment firefighters unexpectedly turned up at a backyard waterslide party and blasted the slide with a powerful jet of water from the truck's hose.

Tiffany Maillet, 34, was at a neighbour's house with her five kids when firefighters arrived at the house next door on a call.

After wrapping up the emergency, one of the firefighters strolled over and made an unexpected offer.

Moments later, a firetruck pulled up and four firefighters unleashed a jet of water from the truck's hose onto the slide, sending the five kids squealing with joy as they slipped and slid down the super-soaked slope.

Tiffany, a-mum-of-five from Lehigh Acres, Florida, said: "The firefighter asked how much water the slide could hold and then asked if it would be okay to spray it with the truck."

"The kids had no idea what was happening and were so confused to see the firetruck pull up."

"One of my sons was standing there asking, ‘Why are they here?' and then suddenly the slide was getting sprayed down."

"They were absolutely thrilled - something they'll never forget for the rest of their lives!"