Scorned

Scorned is a movie starring Billy Zane, AnnaLynne McCord, and Viva Bianca. A romantic weekend turns horrific and sadistic when Sadie discovers her boyfriend is having an affair with her best friend.
Sadie and Kevin have decided to spend a romantic weekend together at his lake house. But when an unexpected- and unfortunate- text from her best friend Jennifer to Kevin reveals a lurid love affair between the two, Sadie spirals into a hunger for revenge.