Desire by Design (Distinguished Rogues, #14)

A surprising offer...

Spinster Sylvia Hillcrest will never marry, but that does not mean she has to ignore the occasional flirtation aimed her way, or the chance to indulge her secret vice in societies best card rooms. When she's suddenly given a fortune to wager, but asked to lose it to one particular family, it's an intriguing challenge too irresistible to pass up. So too is the devilish marquess carelessly flirting with her every chance he gets.

...a secret delight

Faced with a situation he cannot solve alone, the Marquess of Wharton designs a masterful scheme to use Miss Hillcrest's hidden talents for cards to pass a small fortune to a desperate friend. His plan, of course, was destined to succeed, and he spends one scandalous night celebrating with the spinster in his bed. They agreed it was just a fling, but what's a marquess to do when he craves so much more?

Distinguished Rogues Series
Book 1: Chills (Jack and Constance)
Book 2: Broken (Giles and Lillian)
Book 3: Charity (Oscar and Agatha)

Book 4: An Accidental Affair (Merrick and Arabella)
Book 5: Keepsake (Kit and Miranda)
Book 6: An Improper Proposal (Martin and Iris)

Book 7: Reason to Wed (Richard and Esme)
Book 8: The Trouble with Love (Everett and Whitney)
Book 9: Married by Moonlight (Gilbert and Anna)

Book 10: Lord of Sin (Julian and Portia)
Book 11: The Duke's Heart (Sinclair and Kitty)

Book 12: Romancing the Earl (Price and Lenore)

Book 13: One Enchanted Christmas (Otis and Meg)

Book 14: Desire by Design (Alexander and Sylvia)

Book 15: His Perfect Bride (Harry and Ophelia)

Book 16: Pleasures of the Night