A Dog's Breakfast (2007)

"Man's best friend makes the worst accomplice."

Plot Summary

If you've never been good at anything in your life, why would murder be any different? Patrick has always had a somewhat combative relationship with his little sister Marilyn, but when she brings home her new sci-fi soap star fiancé Ryan, it's all out war. When Patrick fails to drive a wedge between the happy couple, he reaches for sharper instruments.