sentences:  Their affair continued on an on-an-off basis for about twenty years, was regarded a scandal and attracted much negative publicity to Duke Charles.Unlike her colleague in the Ballet, Sophie Hagman, who was the mistress of Charles' brother Prince Frederick, Charlotte Slottberg was never allowed to attend the royal court or have any position of an official mistress because of her reputation as a courtesan, and her affair with Charles was in contrast to that of Hagman and Prince Frederick never publicly acknowledged in any way.Their relationship was never exclusive in either part.