Royal expert reveals secret behind Prince William, Kate Middleton's happy marriage

A royal expert has revealed major secret behind Prince William and his wife Kate Middleton’s happy marriage after 15 years of their wedding.

Ingrid Seward was speaking on HELLO!'s live episode of A Right Royal Podcast.

Seward said, "I think what the great thing was that she and William were very good friends before they became lovers.”

The expert said, "She was, in a way, his sounding board. During, I think it was their first vacation from university, he drove to take Catherine out. He drove to her house in Bucklebury and he took her to the local pub, and they had a long, long chat."

She explained: "I can't remember the exact timing. But they were very good friends, and she listened to him and she advised him, and she said, 'Look, if you're not happy doing History of Art, you know, try to do something else. Do Geography or something,' which is what he did. She was such a good friend."

The royal expert’s remarks came as Kate and William celebrated their 15 years of marriage in April.

Sharing a sweet family photo with their children Prince George, Princess Charlotte and Prince Louis, the royal couple said, “Celebrating 15 years of marriage.”

Prince William, the future king, and Kate wed at Westminster Abbey in London on April 29, 2011, in a ceremony watched by millions of people around the world.