Harry's Paternity Mystery Takes The Stage

As Duchess Kate makes headlines for her baby plans, the question of Prince Harry's real father takes to the stage in London. INSIDE EDITION has the scoop.

Duchess Kate is bracing to join the "Two Under Two" club.

She and Prince William are about to experience the joys, and challenges, of having two children who are both less than two years old.

Their first child, George, will be only 21 months when his sibling is born in April.

People magazine Senior Editor Nancy Jeffrey told INSIDE EDITION, "She is going to have to balance the attention she gives him to the attention she gives to a newborn."

The new issue of People magazine, on newstands now, says Kate and William are making the most of their remaining quality time alone with George.

"They recently took him to see Santa and, also, Kate took him on a teacup ride at a London amusement park," said Jeffrey.

Meanwhile, a long-running mystery over William's brother, Prince Harry, is being reignited.

A controversial new play in London is reviving the suggestion that Harry's real father is actually Princess Di's one-time lover, former cavalry officer James Hewitt.

Look at them side-by-side.

Hewitt scoffed at the claim when INSIDE EDITION's Diane McInerney interviewed him in 2011, just before Will and Kate got married.

McInerney asked, "Are you Prince Harry's real father?"

"No, I'm not," replied Hewitt.

Hewitt insisted that he and Diana did not become lovers until after Harry's birth.

But in the new play Truth, Lies, Diana opening January 9, parts of which were reportedly approved by Hewitt, his character says, "Diana and I started our relationship more than a year before Harry was born."

So, the story that has tormented the charming Prince Harry his entire life flares up again.