Their outing to Cardiff on Saturday marked the first time they were at a rugby match since gaining their new titles of the Prince and Princess of Wales.
The Prince and Princess were seen singing the Welsh national anthem – in Welsh, no less! – ahead of the match. But did they stumble over the words?
As Prince of Wales and patron of the Welsh Rugby Union, William will no doubt be backing the Dragons, but as the patron of the Rugby Football Union, Kate will have her support firmly planted with the English Roses.
At the time of writing, Kate will have a big smile on her face, as England leads Wales by 15-10.
Ahead of the match, the Prince and Princess met injured players who are supported by the Welsh Rugby Charitable Trust.
The royals then officially opened the Sir Tasker Watkins Suite – a new space at the Stadium which is dedicated for use by the injured players and their families ahead of matches.
The pair made sure to wrap up warm for the outing, with William in a black coat and red scarf, while Kate looked so stylish in a red and white houndstooth coat.
Princess Kate previously wore the outerwear garment in 2018 when she was pregnant with Prince Louis.
The mother-of-three-to-be stepped out in the luxurious piece during a visit to the Karolinska Institute in Stockholm, to hear about Sweden’s approach to managing mental health challenges. The coat concealed her blossoming baby bump and was teamed with Chanel calfskin bag and sheer tights.