Lord of Pleasure by Erica Ridley

Nondescript “good girl” Miss Camellia Grenville only ever opens her mouth when forced to sing at her family’s musicales. That is, until the night she infiltrates the ton’s most scandalous masquerade ball on behalf of her sister, and finds herself in the arms—and the bed—of the one man she’d sworn to hate.

Irresistibly arrogant and unapologetically sensuous, infamous rake Lord Wainwright always gets his way. When he accepts a wager to turn his rakish image respectable in just forty days, he never anticipates falling for an anonymous masked lover…or that discovering her identity would destroy them both.