Masked Innocence - Innocence Lost, #1

Nothing but a black satin mask protected Lady Katherine Mandeville from discovery and scandal. Temptation lured her to the hedonic masquerade, and eager fascination forced her indulgence in a wicked proposition. A night of paradise, and the most exquisite of sins, enflamed her insatiable desire for the forbidden, leaving her ruined in every possible way. A perfect evening of unparalleled bliss.if only she hadn't been caught. This is a Regency short that ends in a cliffhanger.
It's part of the Innocence Lost series, a group of prequels to Regency romance novels/novellas, each short featuring the defloration of a heroine. These are not required reading to enjoy the Regencies they precede, however they do enhance the story.