Kate Middleton makes rare 3-word remark about Prince Louis after viewing royal portrait

Kate Middleton made a rare playful quip about her youngest son, Prince Louis, during the recent state visit from France.

The Prince and Princess of Wales are parents to seven-year-old Louis, as well as Princess Charlotte, 10, and Prince George, 11.

And for those not up to speed, the British royals have had some special guests for the last three days - Emmanuel Macron and his wife, Brigitte.

The French president and first lady were treated to a full itinerary while over in London, which included a very regal state banquet and a carriage ride to Windsor.

During their three-day trip they spent time with both Prince William and Kate, as well as King Charles III and Queen Camilla.

And on day one of the historic trip, the world leaders got together to view an exhibition of art from the Royal Collection at Windsor Castle.

Kate made a rare comment about Prince Louis during the French state visit (WPA Pool / Getty Image)

Although Kate and William’s children weren’t present in the Green Drawing Room, the Princess of Wales seemed to spot something that reminded her of her youngest - and just had to make a reference.

The piece of artwork in question was a portrait of young King Louis XIV, , who ruled France from 1643 until 1715.

In a conversation seemingly about who was in the picture, as per Hello! Magazine, Kate remarked: “I should know!”

Kate’s love of art is well known and the royal even studied the history of art at the University of St Andrews, so she could have also been referring to this.

And it’s not the only remark the Princess of Wales has made about her children in recent weeks.

She made another rare parenting joke just a few weeks ago during an appearance at Colchester Hospital’s wellbeing garden.

While we regularly see adorable photos and moments from the family-of-five, it’s not often that we see the royal mum and dad get candid about parenting.

Seven-year-old Louis is the Prince and Princess of Wales' youngest (Max Mumby/Indigo/Getty Images)

During her outing, Kate gave fans an update on her cancer journey and opened up on the emotional and physical 'post‑treatment phase'.

She said: “You put on a sort of brave face, stoicism through treatment. Treatment's done, then it's like, 'I can crack on, get back to normal,' but actually, the phase afterwards is really, really difficult."

Kate continued: "You're not necessarily under the clinical team any longer, but you're not able to function normally at home as you perhaps once used to.

"And actually, someone to help talk you through that, show you and guide you through that sort of phase that comes after treatment, I think is really valuable."

In the photos from the event, fans noticed that Kate didn’t seem to want to part from her cup of tea, in very British fashion.

But it turns out the reason she didn’t want to let it out of her sight, actually gave a very relatable glimpse into her life as a mother.

According to the New York Post, she made the joke: “As a parent, you know you'll keep losing your cup of tea.”