Probably refers to a notorious couple, Nicolas de Bauquemare, sieur d'Ons-en-Bray, a President of the Paris Parlement, and his wife, a much younger woman, who always called herself Mme d'Ons-en-Bray while he was known as Bauquemare.
Note from Of Women, the third chapter of 'Characters' by Jean De La Bruyere (1688)