Most Unusual Duke by Susanna Allen

Bridgerton meets New Moon in this sparkling shapeshifter Regency romance mixed with humor, steamy chemistry, and fantasy.
The Duke said he’d never get married…
The Prince Regent insists his cousin and fellow bear shifter Arthur Humphries, the Duke of Osborn, take a mate to ensure the continuation of their species. After all, Arthur is an Alpha, so he must set a good example. The duke would very much prefer to continue his comfortable bachelor lifestyle, but the Prince Regent is not a bear to be poked.
Beatrice, the widowed Marchioness of Castleton, is in possession of a powerful secret. She knows all about Shifters, her horrible late husband being one of them. At any moment, Beatrice could reveal the secrets of the Prince and those like him—unless the Prince can make sure she marries another Shifter.

A marriage between the Duke of Osborn and Beatrice is far from ideal for either one, but at least they won’t fall in love…right?