A council worker joined in the fun when William and Harry spent the morning shifting sandbags in flooded Berkshire.
As the Duke of Cambridge and his brother were snapped by the press, the joker managed to get in on the action by popping into the shot, taken by the news agency the Press Association.
The rather wet royal brothers were in Datchet from 6am helping to organise flood defences in the rain. See more pictures!
Princes William and Harry help out in Datchet today. Looks like they've been photobombed! pic.twitter.com/1C1iCmRjd7— PA Picture Desk (@PAPictureDesk) February 14, 2014