It about about a Duke or Earl and his lady who had been married a a couple of years. His wife started to read a book about how to seduce a man. She thinks her husband is a very responsible and attentive man but just doing his duty when it comes to bedding and leaving her in her own room and returning to his own once bedding is over.
The first scene was when they want to a ball and she had a cloak over her very very exposed gown and her husband only realised it when he helped her out of the cloak after arriving at the party. On the way home in the carriage, his wife seductively suggested that they could make love in the enclosed carriage and they did.
At the last part, he thought she was having an affair when in fact a physician was sent to her to confirm her preganancy.
Can anyone recall the author's name or the name of the book? I had this book + the connected books in hardbacks and I have no idea which of my friends borrow them