Seducing the Viscount — Deborah Raleigh

Illegitimacy is no obstacle for Ian Breckford. Darkly handsome and thoroughly charming, he has bedded his way through London's most exclusive society. Yet this pleasurable existence has lately seemed a trifle dull--a fact soon remedied by a visit to his father's estate, where his aunt has acquired a delightful new companion. Mercy Simpson may be shy, but she is also sharp-witted and stubborn, especially when persuading Ian to relieve her of her innocence...
Ian's arrival presents the opportunity for Mercy to experience uninhibited sensual adventure before she returns to her spinster life. Ian's extraordinary skill is everything she dreamed a lover might offer--and everything she can never hope to keep...unless her brazen seduction can ignite a true, lasting passion...