Prince Harry traded royal protocol for barracks-style humour during a London podcast appearance on July 13, mocking rugby star Joe Marler over an embarrassing toilet confession while one of the Duke of Sussex's closest military friends revealed the habits that make Harry "annoying" on nights out and at home.

The exchange unfolded on the Joe Marler Will See You Now podcast, where Harry had joined Marler to discuss children's resilience, trauma and the challenges veterans face after leaving military service. The conversation took a less formal turn after Invictus Games competitor JJ Chalmers, a longtime friend of Harry, joined the recording.

Chalmers met Harry while recovering from serious injuries suffered in Afghanistan, and their friendship developed through the military and the Invictus Games. That history became evident when co-host Jake Bhardwaj asked Chalmers to identify the prince's most irritating habit.

"Very quick fire. What's the thing he does that gets most on your tears?" Bhardwaj asked.

"So, he leaves the toilet seat up, and he never puts the lid back," Chalmers replied.

Marler responded: "Good. Great. Good."

Harry attempted to give Chalmers an escape route, saying, "By the way, it doesn't have to be anything."

"I can't say nothing," Chalmers shot back, prompting laughter in the studio.

The teasing offered an unusually mundane glimpse of Harry, who lives in California with Meghan Markle and their children, Prince Archie and Princess Lilibet. It also set the tone for a discussion of what socialising with one of the world's most recognisable royals is actually like.

Chalmers said his evenings with Harry have rarely resembled the hard-partying image that followed the prince during his younger years. "We've never had big, big sessions. You're always on your best behaviour," he said.

"A lot of the time when we're out, it's like an Invictus Gala, or it's like some sort of thing. And we're in the corner, the lads, because you know, you get a bunch of veterans together, and you're sometimes like a parent, really. You have to sort of look out," Chalmers added.

The bigger difficulty, Chalmers said, is the attention Harry inevitably attracts. He said he wants his friend to have his "own fun," but Harry's presence brings "extra prying eyes."

"And that, for the record, that's not on you personally. That's the annoying bit," Chalmers told Harry.

Chalmers described spending time with the Duke as "lovely," in part because Harry is willing to engage with people around him. But the same openness can change the atmosphere of an evening as others realise the prince is in the room and begin seeking his attention.

The conversation became considerably more graphic when Marler asked Chalmers: "When was the last time he [expletive] himself?"

Harry drew on his military experience, referring to an episode in the field involving his adjustment to jungle conditions. Rather than provide a lengthy account, he quickly turned the questioning back on Marler and accused the former rugby player of soiling himself "on multiple occasions."

"Yeah, I have," Marler admitted.

Harry's ability to redirect the joke shifted the focus squarely onto the podcast host, producing the kind of blunt exchange more commonly associated with military friends than a formal royal interview.

The discussion also recalled another domestic habit Harry has previously acknowledged publicly: his fixation on switching off lights. In the 2018 BBC One documentary Prince, Son and Heir: Charles at 70, Harry said he inherited the behaviour from his father, then-Prince Charles.

Harry described his father as "a stickler for turning lights off" and said he had become "obsessed" with doing the same.

Prince William, appearing alongside Harry in the documentary, said: "I know, I've got serious OCD on light switches now, which is terrible."

Harry said Meghan quickly noticed the habit while the couple lived at Nottingham Cottage in Kensington Palace. "Which is insane because - I don't know whether your wife doesn't - my wife certainly goes, 'Well, why turn the lights off? You know, it's dark.' I go, 'We only need one light, we don't need like six.'"