An unsuspecting holidaymaker was left mortified when his 'designer' swimming shorts began to dissolve before his eyes.

Father-of-three Dean Hague, 55, from Barnsley, South Yorkshire, was enjoying a day at a waterpark in Portugal when the new shorts, gifted to him by son-in-law Luke Whitham, 28, split in half.

Luke had plotted the embarrassing trick with Dean's wife, Lynne, 50, and daughter, Bethany, 30, behind his back - and the whole party of 12 were there to see it.

In the video, Dean walks from a flume as the shorts begin to vanish - leaving the lab technician's bare bottom on display as he desperately tries to cover it.

Dean gives his shorts a tug and they started to come away after getting out of the pool

The embarrassed father-of-three tried to hide behind the bins after realising what had happened

Farm manager Luke, also from Barnsley, said: 'He's one of those who isn't too fussed about what he wears so his wife buys all his clothes.

'She told him I'd bought him some nice shorts and he thought they were designer. He was blaming Lynne at first.'

Prankster Luke bought the pair of £23.99 shorts from eBay and concocted a plan for Lynne to save them for the day at the waterpark.

He said: 'He came down the slide and got stuck and we were all laughing so he thought that's what we were laughing at - but we knew what was going to happen.

'The shorts started to split and we were laughing our heads off. He was so embarrassed because all the lifeguards were laughing at him.

A child's conveniently placed head covers Dean's bare bottom as the family enjoy his misfortune

Luke had plotted the embarrassing trick with Dean's wife, Lynne, 50 (pictured), and daughter, Bethany, 30, behind his back

'He hid behind a bin to try and get out of public view but all 12 of us were there with our cameras out.

'He is a prankster but he's never done anything like this to me and I know to be aware now.

'If you know him, it couldn't happen to a better person because he's got such a good sense of humour.'