Duchess Catherine was not amused when a London Marathon runner sprayed her and Prince William with water

Photo by: KGC-375/STAR MAX/IPx 2017 4/23/17 Prince William, Catherine, Duchess of Cambridge and Prince Harry at the 2017 Virgin Money London Marathon to benefit "Heads Together", in partnership with eight leading mental health charities, that are tackling stigmas, raising awareness, and providing vital help for people with mental health problems. (London, England)

If looks could kill!

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Duchess Catherine and Prince William were dowsed with water when a cheeky runner at the London Marathon pranked them by spraying them with a water bottle as they went by.

The royal couple and Prince Harry were cheering runners on at the London Marathon on Sunday and by the looks of it, William took the practical joke much better than his wife. According to the Daily Mail, Prince Harry avoided the surprise splash because he was taking a selfie with another competitor.

Photo by: KGC-375/STAR MAX/IPx

William, Kate and Harry were spotted at the starting line for the event and later passed water out to runners during the course. Their charity, Heads Together, was the official partner of the race and works on tackling stigmas, raising awareness and providing vital help for people with mental health problems.

Aside from the little prank, the royals seemed to enjoy their day showing their support for the runners.

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Harry was also spotted greeting runners with hugs ahead of the race.

At the end of the race, the three young royals passed out medals to each one of the finishers.

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