I saw the movie The Stepfather. It stars Penn Badgley (Gossip Girl), Amber Heard (Hidden Palms), and Paige Turco (The 100).
A young man returns home from military school to find his mother happily in love and living with her new boyfriend. As the two men get to know each other, he becomes more and more suspicious of the man who is always there with a helpful hand.
I give this movie 1/5 stars
(It only gets 1 because Penn is in it. Otherwise it would have gotten 0/5 stars. It really is that scary.)