While members of the Royal Family are accustomed to some of the finer things in life, Christmas isn’t an occasion used to flaunt their wealth. Unfortunately, no one told Princess Diana about their long-running tradition when she joined the family for the jolly holiday.

After Princess Diana married Prince Charles in 1981, she was forced to adjust to her new life without much guidance. When the time came for her to celebrate her first Christmas, she made a major mistake that turned their fun gift exchange party into an awkward family gathering.

In the book, “The Queen & Di: The Untold Story,” Ingrid Seward revealed Diana set out to impress her in-laws by buying luxurious presents. However, the Princess of Wales was unaware the family preferred to exchange simple gifts on Christmas day.

“In her generosity, Diana had spent time and money buying what she thought were presents appropriate to her new-found position,” the author explained.

“What she failed to realize because no one had told her, was that in a family which has literally everything, small is beautiful - the cheaper the better.”

Seward claimed Diana was left mortified after she handed out costly items when everyone else brought inexpensive gifts.

“Diana had splashed out on cashmere scarves and expensive bath oils from Floris in Jermyn Street in London’s West End, only to discover that everyone else was handing out £3 woollen socks and 50p bars of soap bought at county fairs.”

While members of the Royal Family reacted to their gifts with “great roars of laughter,” Princess Diana dreaded the moment when her in-laws would open her overpriced presents.

“The sport here was to see who had spent the least, not the most, and Diana’s expensive gifts were received with the polite but withering condescension, which the British upper classes reserve for anyone who does not play the social game according to their rules,” Seward wrote.

The royal biographer claimed Diana said the experience left her “so disappointed,” and made her feel like “an outsider” in her new family.

Although Prince Charles and Princess Diana went on to have two sons, Prince William and Prince Harry, the couple eventually divorced in 1996.

Princess Diana
Britain’s Princess Diana arrives on Oct. 4, 1990 for a charity gala at the Departmental Auditorium in Washington. Kevin Larkin/AFP/Getty Images