Charles was fascinated by her uncommon beauty, her sky-blue eyes, golden hair, and magnificent décolletage emphasized by her low-cut diaphanous gowns that scandalized stricter moralists such as the Flemish poet George Chastelain who lived up to his name by complaining that when he first met Agnes at the French court he could see her nipples!
When Charles met Agnes, she was the mistress of Etienne Chevalier, the king's secretary. Chevalier commissioned Jean Fouquet's portrait of Agnes, which was his masterpiece and one of the more notable paintings of the sixteenth century. This exceptionally sophisticated painting portrayed Agnes as the Blessed Virgin with her left breast bared, for a diptych at Melun. Fouquet also became one of Agnes's lovers along with the royal chamberlain, Pierre de Breze. After Agnes became Charles' official mistress, she dropped Chevalier andFouquet but kept her affair going with de Breze who, although he was in love with Agnes, was politically loyal to Charles.