The titillating title demeans the basic thrust and content here. This is no bedroom farce, and no secrets are revealed. Its subject is the remarkable relationship, as revealed through their letters, between Maria Theresa, Archduchess of Austria and queen of Hungary and Bohemia, and her daughter Maria Antoinette, the doomed dauphine and later queen of France. On the first page we meet 15-year-old Antoinette stark naked in a pavilion in the middle of the Rhine. Why? She was on her way to her arranged marriage with the dauphin, and her Austrian clothes were removed so that she could be dressed in regalia proper to a French princess. When the main protagonists take over the stage through their letters, a drama is unfolded that is at once domestic and historic. In Vienna, there is Maria Theresa, one of the most remarkable--and underrated--women in history. who has managed to keep her Empire relatively intact despite two wars in which France and Prussia were allied against her (Antoinette's marriage was arranged in order to secure a lasting peace with France). Although she believes her daughter ""immature and frivolous,"" the success of the marriage is essential to Austria's interest. And so she admonishes Antoinette to read books, pray assiduously, stop antagonizing Louis XV by snubbing his mistress Mme. DuBarry, and to stop endangering her life by riding in hunts. Most troubling of all: the young dauphin's impotence, which delayed the marriage's consummation for seven agonizing years. In Versailles, there is Antoinette, warm-hearted, pleasure-loving, puzzled by her bumbling young husband's impotence. She dissimulates in the face of her mother's criticism, claiming she is trying hard to read and pray, seldom rides to the hunt, and finally has brought herself to say a few words to DuBarry. Not knowing that the Austrian ambassador to Versailles, the Comte de Mercy, is reporting sub rosa on her every move, she fusses about ""unfounded"" reports of her behavior. Those reports and Maria Theresa's admonitions become thoroughly disapproving after Antoinette becomes queen, plunges into debt through extravagent purchases of jewelry and compulsive gambling. She avoids required public appearances, and influences her husband to install ineffective ministers. With her mother's death in 1780, Antoinette has no good counsel, no one to restrain her excesses. Her path in history now leads to the guillotine, thus fulfilling her mother's 1775 prophesy: ""Your happiness can vanish all too fast and you may be plunged, by your own doing, into the greatest calamities.