The Valet Who Loved Me by Valerie Bowman

He’s on a top-secret assignment.
All of London knows Beau Bellham as the Marquess of Bellingham, but only a trusted few know he also works for the Home Office. His specialty? Scouting out traitors to the Crown. So, when one of his friends pretends to be a footman at a house party in order to find a wife, Beau decides posing as a valet at the same gathering will be the perfect cover for him to spy on the men he suspects of treason. What Beau doesn’t count on, however, is butting heads with a far-too-certain-of-herself maid who gives him hell at every turn.

She’s about to blow his cover.
Miss Marianne Notley is a lady’s maid with more secrets than hairpins. When she meets her employer’s new valet, she distrusts him immediately. Never mind his dashing good looks and irrepressible charm, he’s a bit too sure of himself and asks a few too many questions for her liking. She’s on a mission to reveal the mysterious valet’s true identity, and she’s not above wielding her own considerable charms to do it. But before long, all the pretending Marianne and Beau are doing feels alarmingly real—and a lot like falling in love. When they finally discover the truth about each other, will it spark a face-off for the ages or a love that lasts for all time?