Otherwise Engaged — Sally James

When impulsive Prudence Lee learns that Lord Mottesford has wagered that he can bring her to heel, she determines to play along and then, when he thinks he has won, disillusion him. But Lord Mottesford has some serious problems of his own, which include being trapped into an engagement and suspecting that the dowager Lady Mottesford has somehow disinherited her stepdaughter. Regency Romance novella by Sally James; originally published by My Weekly Pocket Novels