Paul McCartney and daughter Stella McCartneyPaul McCartney’s children are reportedly worried about his new romance with Nancy Shevell - because he has a habit of getting too serious too quickly.

Paul is said to have started seeing Nancy, a New York businesswoman, late last year but after a couple of dates in the US, kept their distance from one another until Paul’s divorce case was tied up last month. Last week they were spotted holding hands and enjoying each other’s company while on holiday together in Antigua.

After objecting to just about every aspect of Paul’s relationship with Heather Mills, his grown-up children Stella, Mary and James are said to like Nancy as a person but worry the relationship is moving too fast so soon, considering that both parties are still tying up divorces from their previous marriages.

A source close to Stella McCartney told the Daily Mail: “[They tell him] he doesn’t have to marry everyone he gets involved with but Paul is an old-fashioned boy and once he has decided he is in love he wants that person to be by his side.”

“He likes being looked after by a wife and he likes waking up with someone next to him. He has been talking excitedly about plans for seeing more and more of Nancy and that worries Stella, Mary and James.”

“Of course, they want him to be happy - that is what they want more than anything else - but things are suddenly moving very fast with Nancy, and the kids are just telling Paul to slow it down a little.”

Soon-to-be ex-wife Heather Mills is also said to be livid about the speed at which Paul’s new romance is progressing and had an argument with the former Beatle when he flew to New York with Nancy late last week: “They had a blazing row as soon as Paul got back to New York and she told him in no uncertain terms that [four year old daughter] Bea was not to be introduced to Nancy until she said so.”

Heather, who is said to have been house-hunting in the city, then flew to Los Angeles for further talks with various media outlets regarding selling her story. The former model wore a black wig at the airport then was spotted with newly dyed red hair yesterday.

A source explained: “She knows her blonde hair is one of her ways people recognise her and she fancies being a little more low-key at the moment.”