In 1738, Pauline wrote to her elder sister, Madame de Mailly, the king's official mistress, asking to be invited to court. She received the invitation, and during her stay proceeded to seduce the king, who fell passionately in love with her.
To provide her an appropriate status at court, the king arranged for her to marry a nobleman only too pleased to leave the couple alone. On 28 September 1739, Mademoiselle de Nesle married Jean Baptiste Félix Hubert de Vintimille, marquis de Vintimille, comte du Luc (b. 1720), who departed to the country after their wedding. The new marquise de Ventimille soon became pregnant by the king.