Daddy's Girls (2017)

A teenage girl (Alison Rey) becomes suspicious of her "perfect" step-father (Ryan Mclane) after he randomly adopts another young woman (Karlee Grey) and brings her to live with their family. Even though dad is boasting about how charitable this makes them, the daughter is convinced he is really using the adoption as a ruse to cheat on her mom. She becomes obsessed with the notion of "catching them" until the adopted sister causes her to confront the REAL issue she is dealing with, her own inappropriate feelings for her step-daddy!