Princess Catherine reveals adorable nickname for Prince Louis

Royal fans are swooning over Prince Louis’ cute family nickname, revealed by his mother at his first official engagement.

Prince George of Wales, Prince Louis of Wales and Catherine, Princess of Wales toast marshmallows as they take part in the Big Help Out. Picture: Getty Images

Princess Catherine has revealed Prince Louis’ adorable nickname as the youngest royals got their hands dirty as part of a nationwide volunteer day following the King’s coronation.

Prince George, 9, Princess Charlotte, 8, and Prince Louis, 5, joined their parents to volunteer for a local Scouts group in Berkshire.

Prince Louis of Wales takes part in the Big Help Out in Slough, England near Greater London. Picture: WPA Pool/Getty Images

Prince William, Prince of Wales is helped by Prince Louis of Wales (L) as he uses an excavator while taking part in the Big Help Out. Picture: Getty Images

In what marked young Prince Louis’ first official royal engagement, the trio of siblings helped revamp the 3rd Upton Scouts Hut in Slough, and were seen painting fences, filling wheelbarrows and sitting behind the wheel of a digger with their dad.

Princess Catherine also let slip her utterly adorable nickname for Prince Louis as the family-of-five roasted marshmallows over the fire.

“Pop that on the fire Lou-bugs,” she instructed her youngest son.

Princess Charlotte (R) shields her eyes from smoke as Prince Louis (C) and Catherine, Princess of Wales toast marshmallows at the Big Help Out. Picture: Getty Images

Prince Louis may have missed out on all the excitement of the King’s Coronation Concert where Prince George and Princess Charlotte stole the limelight, but he was all hands on and funny faces for the Big Help Out.

Prince Louis, Princess Charlotte and Catherine, Princess of Wales. Picture: Getty Images

Prince Louis of Wales and Catherine, Princess of Wales. Picture: Getty Images

He was his usual animated self, pulling faces as he contemplated the taste of the marshmallows and tried his hand at archery.

Prince Louis of Wales eats marshmallows as he takes part in the Big Help Out, during a visit to the 3rd Upton Scouts Hut in Slough, England. Picture: Getty Images

Prince Louis of Wales and Catherine, Princess of Wales toast marshmallows as they take part in the Big Help Out. Picture: WPA Pool/Getty Images

Prince William gave both his sons a ride in the excavator and showed them how to use the mechanical arm to dig soil and dump it.

Prince Louis was spotted filling a wheelbarrow and wheeling it with what looked like construction sand, and dumping it to help reset a path.

Prince William, Prince of Wales is helped by Prince Louis of Wales (L) as he uses an excavator while taking part in the Big Help Out. Picture: Getty Images

Prince Louis of Wales helps his mother, Catherine, Princess of Wales, take part in the Big Help Out. Picture: Getty Image

Princ George was seen working hard with a power tool and drilled holes in a piece of wood.

Prince Charlotte was spotted carefully painting some furniture with wood stain.

Dressed in a mulberry cable knit jumper paired with denim cut off shorts, she also tried her hand at archery.

Princess Charlotte. Picture: Getty Images

Princess Charlotte stains some wood while taking part in the Big Help Out. Picture: Getty Images

The youngsters all wore the Scouts neckerchiefs and seemed happy and content as they helped out for a good cause.

Catherine, Princess of Wales, Prince Louis and Princess Charlotte help to reset a path while taking part in the Big Help Out. Picture: AFP

Princess Catherine and Prince William were all smiles as they showed their kids how to lend a hand.

Watched by his father Prince William, Prince of Wales, Prince George of Wales tries his hand at archery while taking part in the Big Help Out. Picture: Getty Images

Catherine, Princess of Wales, Prince William, Prince of Wales, Prince George, Prince Louis and Princess Charlotte at the Big Help Out. Picture: WPA Pool/Getty Images

Across England, people were encouraged to devote some free time on the Monday of the coronation bank holiday weekend for the Big Help Out, aimed at showcasing volunteering for community or groups such as the Scouts.

Originally published as Princess Catherine reveals adorable nickname for Prince Louis