The princess said today: “These trends come and go. I was saying to my husband, I’m not sure how long he’s going to keep his for.”

Elsewhere, the future Queen enjoyed a sip from half a pint of Guinness after Senior Guardsman Barry Loughlin led a toast of three cheers for her.

Kate spoke to soldiers about their experiences, including those recently deployed overseas and others involved in training Ukrainian troops. In a sitdown chat with a group of troops, she asked them about the difficulties of being on deployment.

She said: “Being able to manage that work-life balance – it’s tough.”

Mr Loughlin said after Kate’s visit: “She wanted to know how things were going with the blokes in general. She was really nice and really warm. I was kind of flustered. You could tell she had a genuine interest in us.”

Kate became the new Colonel of the Irish Guards in March 2023, taking over from Prince William, who had held the position since 2011. He stepped into the role of Colonel of the Welsh Guards, succeeding his father, King Charles.