Prince William and the Princess of Wales (formerly known as Kate Middleton) tied the knot on April 29, 2011.

The pair were married at Westminster Abbey in front of nearly 1,900 guests, with hundreds of millions more watching from around the world. With such a large global audience watching, many thought Kate would be nervous that day. But according to a body language expert, William was the one who was a ball of nerves, and it showed.

Here’s what the expert observed the future king doing over and over as he was a bit of a wreck waiting for his bride to appear and walk down the aisle to where he was.

Expert noticed that Prince William could not hide his nerves and kept doing this

Darren Stanton is a body language and behavioral expert with a degree in psychology. He previously worked as a police officer and used his expertise to uncover the truth when interviewing hundreds of suspects. He later moved into media and TV as a consultant and has been dubbed the “Human Lie Detector.” Stanton shared what he saw from Prince William on his wedding day that revealed just how nervous he really was.

Speaking on behalf of Betfair Slots, Stanton told Showbiz Cheat Sheet: “Prince William appeared tense ahead of the ceremony and was constantly clasping his hands together, which is a sign of apprehension and nerves. I also noticed him biting his lip frequently, which is a common self-soothing gesture used for reassurance. But his body language shows the very real emotions a person can feel on their big day — especially with so many eyes on them.”

Stanton also pointed out how William’s shoulders visibly dropped when he finally saw Kate.

“Despite his nerves, there was a clear change in William’s demeanor when Kate met him at the altar,” the expert noted. “His shoulders dropped and he couldn’t hide the wide smile on his face. He instantly appeared to crack jokes as a way of making Kate feel at ease. They had long periods of eye contact during the ceremony, which indicates a deep and meaningful love.”

Kate was actually much more calm than William and 1 person helped her with that

According to Stanton, Kate appeared a lot less nervous than the groom, explaining: “By contrast, Kate was calm and like William’s rock. She appeared very composed, and when she first walked into the church with her father, Michael, she could be seen smiling and even laughing.

“Michael was clearly a calming influence for her and provided strength. There’s also a sweet moment when Michael is holding Kate’s hand and strokes it with his thumb. It’s very caring and a wonderful father/daughter moment.” 

Stanton added: “It’s really special to see how Kate and William have evolved as a couple. On their wedding day, the love was evident, but they were hesitant about public displays of affection. With their iconic balcony kiss, you can see both Kate and William appear a little bashful.

“But they are now regularly pictured being tactile, and there was even a moment in recent years when Kate slapped William playfully on the bottom on a red carpet. They’re both redefining what it means to be royal and aren’t afraid to show their love and devotion to one another.” 

Showbiz Cheat Sheet acknowledges that conditions and cultures can impact body language and is sensitive to all backgrounds.