By Stephen M. Silverman And Simon Perry
Updated June 19, 2003 10:59 AM

Prince William tasted three shots of Welsh liqueurs at a farm fete Thursday and quipped to the photographers egging him on, “You are trying to get me pissed (a Britishism for ‘drunk’),” PEOPLE reports.

William, who turns 21 on Saturday — and who this week was named one of PEOPLE’s 25 Most Eligible Bachelors — made the lighthearted comment as he sampled some of the local produce during a visit to rural Anglesey, North Wales.

Arriving at the stand of Condessa Welsh Liqueurs, he noticed that they had a bottle of their own cherry brandy — the first tipple Prince Charles notoriously ordered while he was a schoolboy nipping into a Scottish pub.

Condessa owner Julia Jones, 54, tells PEOPLE, “William said, ‘Go on Pops, try it. We all know about it.'”

But Charles, 54, who was accompanying his son on the visit, did not rise to the teasing. “Don’t believe everything they tell you,” he said.

It was an enthusiastic William, who has so often been said to be shy of these events, who threw himself wholeheartedly into the event, going from stall to stall in a food hall, sampling produce, chatting about agricultural issues and checking out herbal remedies.

And he was clearly enjoying himself. When bystanders sang a hearty “Happy Birthday” to him, he waved his arms as if he were leading an orchestra.

After blowing out the candles on a specially made cake — with “Happy Birthday” written in Welsh — he even took part in a steak-cooking demonstration, joking to the staff after his turn behind the stove, “There has been a change of plan — we are staying here.”

William’s more formal birthday celebrations, which will be marked with an official interview and portraits taken by one of Diana’s favorite photographers, Mario Testino, will culminate with a bash at Queen Elizabeth’s Windsor Castle on Saturday night.