Prince William and Kate Middleton split twice before they finally got engaged in 2010. After their second breakup, the Duke of Cambridge had a sudden change of heart.

In the book “Kate: The Future Queen,” royal author Katie Nicholl detailed an incident wherein the second in line to the throne followed the Duchess of Cambridge around like a lost puppy. Prince William also pleaded with Kate to get back together with him.

According to Nicholl, the Duke and Duchess of Cambridge met up at the Clarence House and at a pub close to Highgrove shortly after their split. It was there that Prince William told Kate that he wanted to get back together with her.

Unfortunately, Kate wasn’t ready to give Prince William another chance because she didn’t want to rush into anything. Kate asked Prince William for some time for fear that she would get hurt again.

Weeks later, the future king invited Kate to a fancy-dress party at his army barracks in Dorset. The mom of three agreed to attend the bash because she also realized that she wanted Prince William back.

“Kate was dressed as a nurse — a rather sexy one in fishnet tights and a short dress,” Nicholl said. “[Prince William] followed her around like a lost puppy,” she added. According to the royal author, the Duke and Duchess of Cambridge couldn’t get their hands off each other.

After they got back together in 2007, Prince William waited for three more years before he asked Kate to marry him. When she said yes, the royal couple sat down for their engagement interview.

Kate admitted that she wasn’t happy with her and Prince William’s split years earlier, but she also realized that it was what they needed at that time. In 2011, the couple tied the knot at Westminster Abbey, and they now have three children together.

Earlier this year, rumors swirled that Prince William had an affair with Kate’s good friend, Rose Hanbury. Even though the criticisms thrown at the Duke of Cambridge were quite brutal, Kate still stood by her husband’s side.

Prince William and Kate Middleton Prince William, Duke of Cambridge, and Catherine, Duchess of Cambridge, engage in a walkabout in Ballymena town centre. Charles McQuillan/Getty Images