“I’m gonna die,” says Aaron, 15, as he comes to the end of a stressful session indulging in the latest youth craze. “Definitely gonna die.”

More intense than skateboarding, more addictive than selfies and as inexplicable as anything that has grabbed the collective consciousness in recent years, the latest cult is weird, compulsive and, er, entirely legal.

It is drinking water.

A small group of committed aquaphiles has taken to social media to post short films of themselves drinking bottles of water. And that’s it. There is nothing particularly interesting about the films, which tend to be quite short — less than a minute — and often filmed in the same location. As a spectator sport, competitive water-drinking is on a par with wet paint-watching