Cupid Comes to Little Valentine by Emma V Leech

Sylvester Cavendish, the Earl of Beaumarsh, has never heard of Little Valentine, and if he had, he would never consider visiting.

The spa town of Little Valentine is a charming and sleepy seaside destination, a place the middle classes retire to and the elderly visit to drink the waters. It is far from fashionable and offers none of the entertainment that Beau considers essential to endure another dull day.
Yet Little Valentine is where the earl finds himself, having escaped an untimely death. Beau is well aware his cousin is the culprit, though just how he administered the poison he cannot fathom. But he is all that stands between his cousin Cuthbert and the earldom. Tired of waiting for his wicked relation to drink or debauch himself into an early grave, Cuthbert has taken matters into his own hands.
Yet he had not reckoned on Kirby, Beau’s devoted valet. The ex-prize fighter hauls his lord and master out of harm’s way to recuperate in a place where no one will think to look for him. Sadly, still suffering the ill effects of his cousin’s toxic attentions, Beau makes an immediate impression upon the community, and especially Miss Clementine Honeywell, by vomiting over her shoes.