Princess Anne displayed her sharp wit when she witnessed her son-in-law Mike Tindall's trousers tear at a family gathering.

Celebrating her 74th birthday today (Thursday, August 15), the Princess Royal had a succinct three-word retort upon seeing the cheeky slogan on Tindall's underwear during Zara's 30th birthday bash. The former rugby star recounted the hilarious incident on I'm A Celebrity in 2022.

He shared with campmate Seann Walsh: "I was dancing on the dance floor, I had like flares on, full outfit but it was quite tight, nothing ever fits rugby player's bum and legs so I was dancing with my mother-in-law and I did a s***-drop in front of my mother-in-law.

"Ripped my trousers, straight in front of her. It happened to be that my boxers that I had on at that time said 'nibble my nuts'.

"As I've turned round, she's gone, 'I'd rather not.' I've gone, 'I'm going,' and walked off," reports the Mirror.

Mike and Zara first crossed paths during his participation in the 2003 World Cup. They announced their engagement in 2010 and married a year later.

The couple has since welcomed daughters Mia, 10, and Lena, six, along with their three year old son Lucas.

Despite Mike's close relationship with Princess Anne, he once declined an unusual pre-wedding request from her. She suggested he undergo surgery to fix his repeatedly broken nose before marrying Zara.

Mike declined Anne's half-serious request to straighten his nose, which would have clashed with his training calendar. Sharing the story with Radio Times post-nuptials in 2011, he remarked: "It was a light-hearted, jokey comment. It wasn't a big deal, and look at my nose - can you blame her?"