By Marisa Laudadio
8:46am PDT, Apr 23, 2017
Royals' day out! Britain's Prince William, Duchess Kate and Prince Harry had a blast amid the splashing water, sweaty runners, foam fingers, air horns, hug and selfie-seekers and more as they cheered on and handed out water to participants at the Virgin Money London Marathon on April 23, 2017. The royals, who wore black jackets featuring the logo for their Heads Together mental health advocacy charity — which is the 37th marathon's Charity of the Year — let their hair down for the day that saw nearly 40,000 competitors enter the 26.3-mile race. Keep reading for all the fun photos, starting with this one of William (and an unamused Kate) as he got sprayed by a cheeky runner…
RELATED: Royal family scandals and slipups
Duchess Kate gave a runner dressed as Spider-Man a high-five as Prince William looked on during the 2017 London Marathon on April 23, 2017.
Britain's Prince William, Duke of Cambridge, hugged a runner during the 2017 London Marathon on April 23, 2017.
A runner stopped to take a selfie backdropped by Prince Harry, Prince William and Duchess Kate as they applauded participants at a Heads Together cheering point along the route of the 2017 London Marathon on April 23, 2017.
Prince William and Duchess Kate were entertained by a runner dressed as a star as they handed out water during the 2017 London Marathon on April 23, 2017.
Prince Harry posed with the 2017 London Marathon's Men's Elite winner, Kenya's Daniel Wanjiru, and the Woman's Elite winner, Kenya's Mary Keitany, at the finish line on April 23, 2017.
Prince William, Prince Harry and Duchess Kate — all clad in casual attire and jackets promoting their Heads Together mental health awareness charity — clapped and chatted at the starting line of the Virgin Money London Marathon on April 23, 2017.
Prince William and Duchess Kate had a great time as they handed out water to runners participating in the Virgin Money London Marathon on April 23, 2017.
