According to online magazine Japan FM, Mr Morton said: “In April, much to Kate’s distress, William ended their relationship.
“It was a storm that had been brewing for a long time, resulting from his reluctance to commit and the feeling that his friends noted he could do better.”
A friend of the couple told the royal author Prince William had become increasingly jealous in watching Kate move on from their relationship and soon realised he needed to backtrack on his decision to break up.
The friend said: “He thought he could do better, but realized very quickly what he had given up.
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“William has seen pictures of Kate coming out of Boujis or elsewhere carefree in the world.
“Frankly, he didn’t like the idea of another guy enjoying a hay roll with his girl.”
The source told Mr Morton the breakup ultimately allowed Prince William to secure the relationship his parents had failed to share.
They added: “After the breakup, he achieved what he really wanted in life. A child from a broken house finds love, affection and warmth and a stable family.”
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“In essence, Kate should have changed her schedule, and practically her entire life, to follow her husband’s plans.”
However, taking on the suggestion proved difficult in the first few years of Kate and William’s public relationship due to the prince enrolling into Sandhurst for military training shortly after his graduation from St Andrew’s University.
But since becoming the Duchess of Cambridge in 2011, Kate has been a prominent figure beside Prince William in Royal Family outings.
During the lockdown, Kate moved most of her activities online and joined forces with other members of the Royal Family to help boost the morale of the UK and the Commonwealth.