Kate Middleton's Younger Brother, James Middleton, Is Expecting His First Child with Alizée Thevenet

It looks like Prince William and Kate Middleton won't have to deal with that rumored baby fever any longer, because the princess is about to be an aunt again.

The princess's younger brother, James Middleton, announced on Instagram that he and his wife, Alizée Thevenet, are expecting their first child. He shared photos of Thevenet's baby bump and wrote, "We couldn’t be more excited…well, Mable might be."

"It was a very difficult start to the year after losing my beloved Ella," he said, referring to his first dog. "However, we will end the year with the most precious little addition to our growing family."

James also announced the news on his company Ella & Co.'s official social media page. The pic included another glimpse of his wife's baby bump and two of their dogs. He wrote, "We have a new member of the pack coming soon, we couldn’t be more excited."

This marks the sixth time Princess Catherine will become an aunt. Currently, her sister, Pippa Middleton, shares Arthur (4), Grace (2) and Rose (7 months) with husband James Matthews. And her brother-in-law, Prince Harry, shares Archie Harrison (4) and Lilibet Diana (2) with his wife, Meghan Markle.

James's newest addition will also be the seventh grandchild for Carole and Michael Middleton. Right now, they're the proud grandparents of Pippa's three kids and Princess Catherine's three children—Prince George (9), Princess Charlotte (7) and Prince Louis (5)—whom she shares with Prince William.