Princess Stephanie of Monaco's Son Is Expecting a Baby — and Shares the News with Help from His Dog!

Stephane Cardinale - Corbis/Corbis via Getty Louis and Marie Ducruet

Monaco's royal family is adding another member!

Louis Ducruet — the son of Monaco's Princess Stéphanie and the grandson of Princess Grace (formerly American actress Grace Kelly) — and his wife, Marie Chevallier, are expecting their first child. They shared the news with a sweet Instagram post on Wednesday, using their dog's bandana — which read "soon to be big brother" — to share the exciting news.

"An adventure is about to begin," they captioned the snap.

The pup, named Pancake, has joined Marie and Louis on many adventures documented on their Instagram pages. Marie wrote in tribute to her pet in 2019, "Since the first day we met, spending the day in the train to bring this little boy home, from Paris to Monaco, we knew our lives will never be the same. This boy brought us so much happiness and we can't wait to spend so many more years to come with him ❤️ We love you - Mom & Dad."

RELATED: Prince Albert and Princess Charlene Celebrate Monaco's National Day with Their Twins

Louis and Marie were college sweethearts, together since they met at a Cannes nightclub in 2011 and discovered they were classmates at a nearby business college. Both have described it as "love at first sight."

Louis and Marie, both 29, married in July 2019. They had a civil ceremony followed the next day by a religious ceremony at the principality's Cathedral of Our Lady Immaculate, where the historic wedding of Louis' grandparents — Grace Kelly and Prince Rainier II — took place in 1956.

"I was really attached to my grandfather," Louis said, explaining the couple's choice of venue. "And I wanted him to be here with me. At some point, he will be with me during the wedding ceremony at the cathedral. That's why we chose it, and Marie supported me in this decision, even though the place is big and there's a protocol, but that's the only way for my grandfather to be with us."

David Niviere/SC Pool - Corbis/Corbis via Getty

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Louis and Marie joined the rest of Monaco's royal family for National Day celebrations over the weekend. Marie wore a pink jacket over a dress with a statement headband for the occasion.