The Well-dressed Werewolf by Gillian St. Kevern

When the full moon is a black-tie event.
Felix Wood, valet, is determined to halt his employer’s downward spiral. Just because the man is a vicious beast three nights a month doesn’t mean he can’t be an impeccably dressed gentleman the rest of the month. Felix’s commitment to duty convinces Westaway, a man of more wealth than sense, that Felix is the valet he—and his large wardrobe—deserve. There’s just one problem: Felix already has a gentleman, and his presence is the only thing between Robin and self-destruction.
When a werewolf and his keeper are brutally murdered, Westaway and Felix must work together to prevent the Society of Lycanthropes and their Keepers being ripped apart. But even as he risks his life to save Robin, Felix finds himself drawn closer to Westaway, in an attraction that could destroy everything he values.