By Isabel Jones
Jul 10, 2018 @ 10:15 am

What's so funny, Prince William? 

The Duke of Cambridge, alongside wife Kate Middleton—who broke her maternity leave for a surprise appearance at a service for the Royal Air Force centenary at Westminster Abbey (the site of her 2011 royal wedding)—couldn't help but let a smirk slip on Tuesday morning.

Simon Dawson - WPA Pool/Getty Images

In a candid video of the royal duo, Wills and Kate are just casually waiting for the service to commence—Kate looks pretty bored, honestly, or more likely, worn out from three kids under 5—when a sly smile begins to spread across William’s face. He appears to be on the verge of laughter when Kate—decked out in pale teal Alexander McQueen (her go-to designer) and a matching floral fascinator—catches him in the act. As the camera pans out, it looks like the Prince is explaining what’s so funny to his wife, the answer to which appears to bring a smile to Kate’s lips as well.

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Kate and William don’t often engage in public shows of affection (unlike their newlywed counterpart Meghan and Harry), so it’s nice to see them sharing an intimate moment in the very place their royal love story began.