They have had a very long marriage and he has even been known as wife’s main source of strength over the years. However, Prince Philip’s love of pranks once led to a major battle with his wife that left him questioning her reaction.

According to Express UK, though Queen Elizabeth usually shares her husband’s sense of humor, one joke in particular once overstepped the mark considerably. An insider told the website that during one dinner they held, the Duke of Edinburgh hid one of his wife’s prize Corgi pups to impress a guest—but the move outraged the Queen when she realized what he had done.

“Philip hid a corgi in a desk cupboard and when the Queen asked him where it was, he said he didn’t know,” the source told the website. “But then the dog whined after hearing the Queen’s voice, so Philip let it out and it ran to her.”

However, the Queen wasn’t amused by the joke and scolded her husband to “stop showing off,” before leaving the room. Afterward, Prince Philip was also not impressed with his wife’s reaction, and the source revealed that he then lashed out after she left the room.

“Philip turned to the guest and said ‘who does she think she is?’” the source said.

Of course, the incident doesn’t serve as an indicator of the couple having trouble in their marriage, which is now more than seventy years strong, though things have reportedly changed in their later years, specifically after Prince Philip retired from royal duties in 2017.

Since then, he spends a majority of his time at the Sandringham Estate in Norfolk, while the Queen remains busy with her duties at Buckingham Palace most days. However, the two are both usually still present for major events and functions, including the weddings of Prince Harry and Meghan Markle and Princess Eugenie and Jack Brooksbank in both May and October 2018.

Queen Elizabeth II, Prince Philip
Pictured: The Queen, Prince Philip depart a Service of Commemoration for troops who were stationed in Afghanistan on March 13, 2015 in London, England. Getty Images/Chris Jackson