Lord of Scoundrels by Loretta Chase

Tough minded Jessica Trent's sole intention is to free her nitwit brother from the destructive influence of Sebastian Ballister, the notorious Marquess of Diain. She never expects to desire the arrogant, amoral cad. And When Daine's reciprocal passion places them in a scandalously compromising, and public, position, Jessica is left with no choice but to seek satisfaction... Damn the minx for tempting him, kissing him...and then for forcing him to salvage reputation! Lord Dain can't wait to put the infuriating bluestocking in her place -- and in some amorous position. And if this means marriage, so be it -- though Sebastian is less than certain he can continue to remain aloof...and steal his heart to the sensuous, head strong lady's considerable charms.

Binding: Paperback