Reality TV host Maya Jama tried to recruit a new fan when she asked the King if he watches Love Island during a Buckingham Palace garden party celebrating the creative industries.
Charles laughed and made jokes with guests as he joined the Queen, Duke of Edinburgh and Duchess of Gloucester in the palace garden on Wednesday.
Laughing, the King quipped in response: “There’s one born every minute.”
When asked about her future plans, she told him: “I’m just about to go to Spain to film some young people snog someone.”
Theroux, 53, told the PA news agency he was “very flattered” to have been invited and was in such disbelief that he felt it “must have been a mistake”.
“I couldn’t tell if (Charles) was a fan, but I would love to say he is.”
Sir Ridley, who has directed Hollywood blockbusters including Gladiator and Alien, said he was “incredibly honoured” to have been invited.
When asked if Charles was a fan of his films, he said: “No idea. But they’ve to watch something at night don’t they?”
Sir Ridley was made a Knight Grand Cross by the Prince of Wales during an investiture ceremony at Windsor Castle last week.
Charles, wearing a grey suit and pink waistcoat and top hat, smiled to the gathered crowd as he entered the garden from the palace.
Camilla wore a pale pink fringed coat dress by Anna Valentine with a co-ordinating Philip Treacy hat, and accessorised her outfit with the late Queen’s pink diamond flower brooch.
Charles and Camilla then greeted groups of attendees separately.
Artist Tracey Emin told PA the Queen in particular had remembered both her and her work.
The King has been receiving treatment for an undisclosed form of cancer since early February but has returned to public duties including conducting his first investiture ceremony for five months at Windsor Castle on Tuesday.
