My best friend is a werewolf

Tessa (aka Tess) and Zach have been best friend since Tess was born. They do everything together. One night Zach takes Tess out to the woods and shows her the side of him she has never seen before. Will Tess still want to be his best friend even though she know the bad side of him? Or will she part the friend ship and leave Zach in the dust?