Demi Lovato is still laughing over her late night “water fight”.

The 21-year-old pop star is currently on the road for her Neon Lights Tour.

And it seems the singer and her crew members are filling up their downtime by getting up to silly pranks.

Demi posted a 30-second video on Twitter on Monday, sharing their hijinks with fans.

“1am water fights on the bus. Hehe #NEONLIGHTSTOUR,” she wrote after Saturday night’s concert in Grand Rapids, Michigan.

The clip shows a man on Demi’s tour bus splashing water out of a bottle as girls appear to scream in the background.

Demi has kept her fans updated on all of the ups and downs of life on the road lately, and most recently shared she was celebrating her “2nd birthday” by getting a little body art.

“Today is my 2nd birthday. I'm 21 years old, but 2 years ago today, I finally started living.. I'm so beyond grateful..#ItWorksIfYouWorkIt,” Demi tweeted earlier this month, referencing a common phrase from the Alcoholics Anonymous 12-step programme.

“Why not celebrate with some new piercings? 4 in one sitting.... #whoops!! #sorrynotsorry,” she revealed.

Demi shared a photo of her ear, which featured a few new holes, filled with new studs and rings.

The singer is next scheduled to play in Toronto on Wednesday night, before trekking through the US, South America and North America, wrapping up the tour in Monterrey, Mexico on May 17.