Some college seniors celebrate the final week of school with a keg party. If you're William Wales, hitting the homestretch calls for a sport of kings: Just before his 23rd birthday (June 21) and his graduation (June 23), the prince enjoyed a weekend of polo near his father's Highgrove estate—cheered on by royal relations and joined by girlfriend Kate Middleton, 23. Watching the action on June 18, Will delighted onlookers at the Beaufort Polo Club by flirting with Middleton in the stands and licked ice-cream cones with her amid the heat wave. "It's nice," says a family friend, "that they are not shy of being seen like this."

After a quiet birthday celebration at Highgrove, the pair were scheduled to return to Scotland for commencement and yet more royal revelry—Queen Elizabeth, Prince Philip, Prince Charles and his wife, Camilla, were all expected to be on hand to congratulate William when he received an honors degree in geography. Next up: William makes his first solo royal tour, visiting New Zealand in July, then may meet up with Middleton and friends later in the summer for an African holiday. As for the future, the prince will likely follow kid brother Harry into Sandhurst military academy next year. Expect weekends to be booked. Says royal expert Robert Lacey: "William's willing to let the world know about Kate."

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