Step Brother Bear by GM Fairy:
 
Her step-brother is an animal, and she is his prey.

Isabella has always hated her unruly step-brother, Derek. Luckily for her, he spent most of their lonely upbringings at a boarding school for troubled kids. Now that she’s an adult and back in her childhood home, she hates the tattooed, moody man even more. Mostly because he’s right next door, set on making her life miserable and behaving like a literal animal. Things get even worse when her mom and step-dad leave town and task her to care for the beast and his newly acquired gunshot wounds. Their close quarters reveal heated secrets with monstrous consequences. There’s more to Derek than meets the eye, leaving Isabella to excavate terrifying and confusing feelings.

Can she see past the claws, or will she decide the two are just entirely different species?