"I hate doing this," he muttered under his breath and, "Bloody people," as he smiled wryly, apparently blissfully unaware that microphones on the ground in front of him were picking up every murmur.
But the prince's ire seemed mostly directed at the normally inoffensive BBC royal correspondent Nicholas Witchell, a man once known to his colleagues as the bionic carrot and hitherto most famous for sitting on a studio-invading lesbian demonstrator while he carried on reading the Six O'Clock News.
"I can't bear that man anyway. He's so awful, he really is. I hate these people," Charles added as a not so sotto voce running commentary to his sons when Mr Witchell ruthlessly probed the prince's feelings about his forthcoming wedding. For public consumption, he merely said: "I am glad you have heard of it."
The mumbled exchanges began with Charles asking his two sons: "Do I put my arms around you?"