Prince William appeared to be caught on camera swearing as he watched a Wimbledon match.
The Duke of Cambridge was spotted by eagle-eyed viewers during British No1 Cameron Norrie's quarter-final clash saying: "No, no, no, f***' in the Court One crowd.
The royal, 40, is a major sports fan and appeared to get caught up in the moment as the 26-year-old star lost a point to Belgian David Goffin on Tuesday evening.
As Norrie was seen wheeling away in frustration after slipping up in his own service game, the BBC coverage cut to an equally annoyed Duke.
He shook his head from side to side before seemingly uttering the expletive as he straightened his tie.
South Africa-born Norrie dug deep to come from behind and eventually beat his opponent and set up a semi-final meeting with World No3 Novak Djokovic.
The defending champion, 35, from Serbia, beat Italian Jannik Sinner earlier in the day.
William was much more relaxed during that match, joined by wife Kate in the Centre Court royal box.
The Cambridges were both seen grinning as they each sported sunglasses for their first trip to the All England Club of the year.
Twitter users were gobsmacked by William's expletive after the clip was shared on the social media site.
However, most saw the funny side.
One person wrote: "Can't be unseen! So glad he's human."
Another said: "Good to see some feelings."
Some pointed out that he may well have been saying "for goodness sake" as the camera cuts away quite rapidly - though most were not convinced.
Meanwhile, Norrie fired a warning at his upcoming opponent after his dramatic win.
Asked if he thinks he can beat the former world No1, Norrie said: “For sure. I’m looking forward to taking it to him and seeing the level he brings.”
But after struggling for large parts of his three-and-a-half hour contest against the unseeded Goffin, Norrie knows he will have to up his game against Djokovic, who is gunning for a 21st Grand Slam triumph.
He added: “I'm going to have to improve a lot of things. I don't think I'm going to have the chance to lose focus like I did against David. I think I was a little bit fortunate."
