Royals Spencer Matthews Shares Never-Before-Seen Snap from Wedding with Kate's Brother, James Middleton These brothers-in-law are close buddies By Stephanie Petit Stephanie Petit Stephanie Petit is a Royals Writer and Reporter at PEOPLE. People Editorial Guidelines Published on January 11, 2019 09:42 AM Share Tweet Pin Email Trending Videos Photo: Spencer Matthews/Instagram Brotherly love! After spending a sunny New Year’s family vacation in St. Barts with brother-in-law James Middleton, Spencer Matthews shared a peek into their bond on Thursday with a throwback photo. The joyful shot, set against a scenic lake, captures the two pals mid-air while dressed in their top hats and suits at Spencer’s June 2018 wedding to model Vogue Williams. Spencer – whose brother, James Matthews, is married to Kate Middleton‘s sister, Pippa – paid tribute to his wife and the mother of their son Theodore, born in September, in the caption. “Thought I’d share this fun snap of @jmidy and I on my wedding day to the one and only @voguewilliams!” the former reality star, 30, wrote. “What an amazing weekend that was… Feel lucky every day to be married to her.” Can’t get enough of PEOPLE’s Royals coverage? Sign up for our newsletterto get the latest updates on Kate Middleton, Meghan Markle and more! Tagging Kate’s younger brother, 31, in the playful snap also helped royal fans discover that James had made his Instagram account public, allowing fans to see hundreds of photos that date all the way back to 2013. Looking at the page, James’ love of animals is clear. On New Year’s Eve, he praised his dog Ella for becoming a Pets As Therapy (PAT) dog. He has also shared photos of at least eight other dogs, including one shot surrounded by his pack, which includes a Golden Retriever, a black Labrador, and several Cocker Spaniels. James and Spencer kicked off the new year with a family vacation in St. Barts that also included Pippa, her husband and their 2-month-old son, Arthur. Spencer documented the beach holiday on Instagram, including photos with his family. “Feel most at home on this island. It’s where I grew up,” he wrote on Instagram. “Absolutely delighted to finally share it with my wife and son.” James was spotted enjoying the sunshine with Alizee Thevenet, a French financial analyst based in London. He has yet to share photos from their adventure.