Both husband and wife had lovers, and in 1778 Bathilde gave birth to an illegitimate daughter, Adelaïde-Victoire, who was registered under the surname Dumassy (and not Damassy as was often mentioned in genealogical works). Her father was a young naval officer, Alexandre Amable de Roquefeuil. The relationship ended in tragedy when de Roquefeuil drowned in Dunkirk harbour in 1786. The scandal of the duke's adultery came out in 1778, and the consequences fell entirely on Bathilde's shoulders; she was believed to have commissioned a play from Pierre Laujon which featured a thinly disguised Duke of Bourbon and his mistress. The couple formally separated in 1780.