Pippa Middleton at US Open
Pippa Middleton, the sister of Catherine, Duchess of Cambridge, arrives at the gallery at the U.S. Open tennis tournament in New York, 4 September, 2012. REUTERS/Eduardo Munoz

Pippa Middleton, the sister of Catherine, the Duchess of Cambridge, may be moving to New York City.

The youngest Middleton sister has been in New York for the past week, and spent the Labor Day weekend in the Hamptons. According to the Daily Mail, hotelier Andre Balazs, 55, reportedly worth more than $450 million, flew her by seaplane to his resort, Sunset Beach, on Shelter Island on Sunday. They are rumored to be dating, though he is much older.

They went out to dinner together, and a diner sitting newarby told the Daily Mail: "They didn't seem like a couple but there was a lot of flirting going on and when dinner ended he gave her a friendly European-style double kiss on the cheek."

On Wednesday, Middleton watch some tennis matches in Flushing Meadows at the U.S. Open, cheering for Andy Murray as he won his quarter-final match.But the most interesting outing she has taken during her time in New York was paparazzi shots snapped yesterday show Middleton house hunting on Madison Avenue with a woman Splash News describes as a realtor.

Earlier this year, it was also rumored that Middleton would be moving to New York. British magazine Grazia reported that the 29-year-old "left her part-time job at Table Talk amid talk among her circle that she could move to America."

As she has a party-planning book set to launch in New York on October 30, she will be spending a lot of time in the Big Apple, though a spokesperson for Middleton told Grazia she has "no plans" to move abroad.