Historical romance with paranormal elements? Vampire/demon hunting I think?

[SexySiren24]

Hey guys! I've been looking for this book that I read a sample of once (and then prompty deleted) to maybe actually read this time.
It was a paranormal historical romance featuring this group of young women who hunt vampires/demons/some kind of supernatural beings.
IIRC the main character's bf comes back from gallivanting around the continent to marry her and sees her sneaking off from a ball with some dude, so of course he gets upset and follows her, only to find her killing the guy, so she has to come clean about her activities and eventually he joins their group I think.
I don't know the exact year of publication, but it must be mid 2000s at the oldest, when urban fantasy/pnr was at its peak. It's also a shorter novel I think, or even a novella, and I don't remember it having a ton of reviews, so maybe something not so popular.
Thanks!