The royal family attended a memorial service for the Queen Mother and Princess Margaret. Photo: Getty
She may have recently lost two stone, but Princess Beatrice was determined not to have a VPL (visible panty line) at a memorial for the Queen Mother and Princess Margaret - by donning a pair of supportive Spanx.
The split at the back of her pretty floral Paul Smith dress inadvertently gave her style secret away.
Princess Beatrice's Paul Smith dress revealed her Spanx. Photo: Getty
She teamed the flower power frock with a Sarah Davis fascinator and LK Bennett heels for the service at St George's Chapel in Windsor.
Of course, the princess is in good company among fans of the figure-shaping shorts and tights, with everyone from Beyoncé to Sarah Jessica Parker having previously flashed theirs.
And the brand is so successful that, at 41, its founder, Sara Blakely, was recently the youngest self-made woman to make it on to the Forbes' Billionaires list.
Princess Beatrice was joined by a host of other royal family members for the service, apart from the Duke and Duchess of Cambridge, who are enjoying a skiing holiday in Switzerland.
- April 1993<p> Princess Beatrice and Princess Eugenie as bridesmaids at Alison Wardley's wedding.</p>

- December 1995<p> The Duchess of York with her daughters Princess Beatrice and Princess Eugenie. Here they are attending Christmas pantomime 'Cinderella' in aid of 'Children In Crisis.' </p>

- July 1998<p> The Duchess of York arrives at Londons Appollo Theatre with Eugenie and Beatrice to see Dr Dolittle.</p>

- July 2000<p> Princesses Beatrice and Eugenie, the daughters of Prince Andrew and Sarah Ferguson, attend a thanksgiving service for Britain's Queen Mother at St. Paul's Cathedral in London.</p>

- December 2004<p> Princess Eugenie, Sarah Ferguson and Princess Beatrice arrive at the Palace Theatre to watch 'The Woman in White.'</p>

- December 2004<p> Beatrice, Sarah Ferguson and Eugenie arrive at the UK Premiere of 'The Aviator.'</p>

- Princess Beatrice and Princess Eugenie<p> Princess Beatrice, Princess Eugenie and Sarah Ferguson, the Duchess of York </p> <p> </p>

- December 2006<p> Sisters Beatrice and Eugenie attend Christmas Day service at Sandringham Church in Kings's Lynn, England. </p>

- September 2008<p> Princess Beatrice, Naomi Campbell and Princess Eugenie pose backstage during the ISSA fashion show at the Natural History Museum. </p>

- March 2009<p> Duchess of York, and her daughters Princess Eugenie and Princess Beatrice attend the world premiere afterparty for 'The Young Victoria.' </p>

- June 2009<p> Princess Eugenie and Beatrice attend The Ralph Lauren Sony Ericsson WTA Tour Pre-Wimbledon Party, at The Roof Gardens.</p>

- September 2009<p> Sarah Ferguson, the Duchess of York with Princesses Eugenie and Beatrice of York attend 'The Young Victoria' Premiere held at Roy Thomson Hall, during the 2009 Toronto International Film Festival. </p>

- October 2009<p> Princess Beatrice and Princess Eugenie attend Sarah Ferguson 50th birthday Party held at Lanesborough Hotel. </p>

- December 2009<p> Princess Beatrice and Princess Eugenie arrive at 'The Young Victoria Los Angeles Screening,' at the Pacific Theatres.</p>

- December 2009<p> Eugenie and Beatrice attend the VIP reception to launch the English National Ballet Christmas season, ahead of the performance of 'The Nutcracker.'</p>

- March 2010<p> Princess Eugenie and Princess Beatrice attend the launch of 'The Elephant Parade.' </p>

- June 2010<p> Princess Beatrice of York and Princess Eugenie of York study their race cards as they attend Royal Ascot Ladies Day.</p>

- June 2010<p> Princess Beatrice and Princess Eugenie attend The Elephant Parade auction in aid of The Elephant Family.</p>

- December 2010<p> Princess Beatrice walks with Princess Eugenie after attending the Christmas Day Church Service at St Mary's Church.</p>

- April 2011<p> Eugenie of York and Beatrice of York arrive to attend the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey. </p>

- June 2011<p> Princess Beatrice and Princess Eugenie arrive for the opening day of Royal Ascot at Ascot Racecourse. </p>

