Their children, Pippa and James, were in the royal box last week, but on Tuesday it was Carole and Michael Middleton's turn to preside over the day's play at Wimbledon.
It was a step up for the Duchess of Cambridge's mother, who was spotted in the regular stands at the All England Club last Wednesday.
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And while their son and daughter cheered on Andy Murray, Carole and Michael checked out his opponent in the quarter finals, David Ferrer, as the Scotsman battled the elements on Court One.
A rainy day at SW19 meant that while Prince William's mother-in-law was able to watch the action under the comfort of the Centre Court roof, much of the day's play was suspended due to intermittent showers.
Despite a match heavily disrupted by the elements, Andy Murray was able to finish off his oppponent, Marin Cilic, in three sets.
Joining Carole and Michael in the royal box was the Queen's cousin Prince Edward, the Duke of Kent, the All England Club president and Bahraini royal Sheikh Mohammad bin Mubarak al-Khalifa.
Other spectators included Giles Clarke, chairman of the England and Wales Cricket Board; veteran war correspondent Max Hastings, British mezzo-soprano Katherine Jenkins, Harry Potter actress Bonnie Wright; and Britain's 2000 Olympic heptathlon champion Denise Lewis.
Last year, Kate's parents they cheered on Roger Federer with Pippa and her then boyfriend Alex Loudon.
The visit to SW19 comes just two weeks after sharing jokes with the Queen and Prince Philip at Ascot.
Carole, 57, was resplendent in a traffic-stopping red dress that resembled the scarlet Alexander McQueen number Kate wore to wow the crowds at the Jubilee Thames River Pageant.
Just as she did the previous year, Kate's parents rode in the monarch's carriage procession.