London, April 14: After receiving his RAF wings, British royal Prince William let his hair down in a 72-hour fun-filled booze bender.

The young royal dropped his trousers and downed pints of bitter as he and brother Harry gave their royal cousin, Princess Anne’s son Peter Phillips, a boozy stag weekend to remember.

The bash began on the morning of April 11 as the stag party boarded a high-speed ferry from Southampton to Cowes on the Isle of Wight.

William and Harry arrived to join the fun, following the former’s RAF ceremony in RAF Cranwell, Lincs.

And within hours the revellers headed to a pub, where they rubbed shoulders with puzzled locals.

“I was just sitting watching the band when Prince Harry came over holding a funnel and a pint of beer and said I had to have a drink,” The Sun quoted astonished local Sophie Bleak, 39, as saying.

“He put the funnel in my mouth and began pouring lager down it — but after two gulps I had to give up. He laughed, gave me a big hug and told me to have a good night.

“It was incredible seeing those two guys in here out on the beer with just the ordinary locals. Harry and William were as good as gold.

"They drank until the music ended, then left with the police officers who were looking after them,” she added.

At one point, after hours of heavy drinking, William and Harry, were heard panicking because Peter apparently was lost.

Harry screamed: “I do bad things to bad people. Where the f*** is the stag? We’ve lost the f****** stag.”

After a frenzied search, Peter was found slumped in a shop doorway. The party then headed to their hotel with a crowd of girls in tow.

At 2am Wills, a girl mate and two lads went into a function room and began playing drinking games.

On the morning of April 12, the 23- strong group went to Cowes marina for a day’s sailing. Once on board, Peter was quickly forced to down a “hair of the dog” drink of beer mixed with vodka.

On their second night, the party forced Peter into a purple lycra catsuit with red briefs over the top and taped a pint glass to his hand.

“They may all have been three sheets to the wind all weekend but it was all in good humour. There wasn’t a hint of any trouble, it was just a great laugh,” a pal said.

Peter is due to wed fiancée Autumn Kelly, 29, at St George’s Chapel at Windsor Castle on May 17. (ANI)