This is book number 6 in the True Gentlemen series.
Grey Dorning, Earl of Casriel, must marry well and soon. He has five unmarried brothers whom he should assist to get a start in life, any number of tenant cottages threatening to fall apart, and he's running out of time to set the earldom to rights. He needs an agreeable heiress looking for a title, a lady who will be content to marry a man more renowned for his manners than his fortune.
Beatitude, Countess of Canmore, wants a friendly, harmless liaison with a charming man who won't fetter her freedom. She's not wealthy, but she has earned her independence, and intends to keep it. Casriel knows what he needs, Addy knows she wants, so why can't they stop thinking about each other?