A Gift for a Rogue — Julia Parks

HIS REPUTATION WAS ABOMINABLE...
After years as one of London's most notorious rakes, Alexander Havenhurst, Earl of Foxworth, has decided to settle down. He longs for the sort of storybook marriage his brother enjoys, but his reputation keeps most suitable ladies from taking him seriously. With pride bowing to need, Alex has but one option left--to consult a professional matchmaker who can give him the polish he lacks. And the only matchmaker who will agree to help him is the lovely widow Lady Isabelle Fanshaw, whose sparkling green eyes and ready wit do nothing to help his efforts to reform.

...AND VERY TEMPTING
Lady Isabelle has guided many a young lady through the pitfalls of the social season. But how can she tame such a rake as Alex Foxworth, a man with manners more suited to a brothel than the drawing room? When the lout insists that he must flirt with someone, or go mad, Isabelle agrees to let him engage in some harmless repartee with her, as long as he behaves as a perfect gentleman in public. But as an important Christmas house party draws near, Isabelle realizes that her tutoring may be succeeding all too well. For she soon has no desire to see her beloved rake in any woman's arms but her own.