Prince Harry and Pippa Middleton
Prince Harry and Pippa Middleton on the balcony of Buckingham Palace after the Royal Wedding of Prince William and Kate Middleton on 29 April, 2011Getty

A US tabloid has come up with sensational claims that Prince Harry and Kate Middleton's sister have been secretly dating. OK! Magazine reports that the 31-year-old royal and Pippa Middleton have been enjoying a "secret romance" since three months.

"They're trying to play it coy," an alleged insider said, according to Daily Mail. "But there's no doubt that this is developing into something serious. They're truly sweet together and, in fact, seem very much in love."​

"There's always been sexual tension between them, even when they were dating other people," the insider added. The publication also claimed that Harry and Pippa got close during her sister's fairy tale wedding to Prince William in 2011. The source continued: "At one point, Kate went to check her make-up and found them snogging in a bathroom."

In October, Pippa split from her boyfriend Nico Jackson as she was not ready to settle down. Pippa, 32, and millionaire stockbroker Jackson parted ways after dating for more than two years.

Previously, during an interview with Sky News' royal correspondent Rhiannon Mills, Prince Harry, who has been voted among the world's most eligible bachelors, spoke of his desire to have children.

"There comes times when you think now is the time to settle down, or now is not, whatever way it is but I don't think you can force these things, it will happen when it's going to happen," he said.

"Of course I would love to have kids right now but there's a process that one has to go through and tours like this are great fun, hopefully I'm doing all right by myself, it would be great to have someone else next to me to share the pressure, but you know, time will come and whatever happens, happens," Prince Harry added.

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Posted by OK! Magazine on Wednesday, 9 December 2015