Taming the Wicked Wolf by Kenzie James

Emilia turns to magic in a last ditch effort to protect herself from her ex-husband, who can’t seem to take a hint. One pricey ritual and a potentially ruined dining room floor later, she’s left with a wolf demon, but not the one she expects.
Silas has one job, play bodyguard to a powerful witch in exchange for her soul. The deal seems simple enough until he finds himself at the end of her leash.
As he helps Emilia find her strength, Silas realizes he desires more than he bargained for, he wants her heart as well.

Taming the Wicked Wolf is a mild-angst, high-steam standalone paranormal romance novella under 30k words with a guaranteed happily ever after.