There’s a baby on the way for Monaco’s royal family!
With Prince Albert on a state visit to South America, all eyes at the Bal de la Rose turned to Princess Caroline’s family entrance to the 64th annual soirée on Saturday.
Looking radiant, daughter-in-law Beatrice Borromeo, 32, wore a black velvet Alberta Ferretti Empire-style gown as she cradled her baby bump. Soon-to-be father of two Pierre Casiraghi, 30, who is currently 7th in line of Monaco’s succession, dressed in a black tuxedo.
Sources at the Bal tell PEOPLE Beatrice is due in May.
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Just last year at the same glamorous Monte Carlo event, Beatrice and Pierre, who met in college and have been together since 2008, made their first post-baby public appearance together.
The child will be Caroline’s fifth grandchild. Prince Albert has previously told PEOPLE how his sister Caroline was looking forward to the expansion of her royal family.
“She’s a very good mother, and probably an even better grandmother now if that’s possible,” Albert said in January 2017. “She really raised her kids well. Without a father for many years, that’s important. I’m incredibly proud of her children and to have them turn out as they have — that’s a tribute to her.”
Also at this year’s Bal de la Rose, Pierre’s sister Charlotte Casiraghi confirmed her engagement to Dimitri Rassam by wearing a diamond ring on her left hand.