Not Proper Enough (A Reforming the Scoundrels Romance) - Carolyn Jewel

The Marquess of Fenris has loved Lady Eugenia from the day he first set eyes on her. Five years ago, pride caused him to earn her enmity. Now she's widowed, and he's determined to make amends and win her heart.
But with their near explosive attraction, can he resist his desire long enough to court her properly?

After the death of her beloved husband, Lady Eugenia Bryant has come to London to build a new life. Despite the gift of a medallion said to have the power to unite the wearer with her perfect match, Eugenia believes she won't love again. And yet, amid the social whirl of chaperoning a young friend through her first Season, she finds a second chance at happiness.

Unfortunately, the Marquess of Fenris threatens her newfound peace. Eugenia dislikes the man, but the handsome and wealthy heir to a dukedom is more charming than he has a right to be. Constantly underfoot, the rogue disturbs her heart, alternately delighting and scandalizing her.
And when their relationship takes a highly improper turn, Eugenia must decide if the wrong man isn't the right one after all.