Usually when it comes to a ghost movies, I'm uninterested, if they don't have actual physical form that can hurt you like in the Grudge or Ring series.
In this movie, the ghost doesn't have physical form, yet can hurt you, and Oh boy, did he hurt this poor guy!
Why? Because the unaware guy was banging his ex wife that he abused and couldn't let go even after his Death.
Quite a horrifying idea.
Enjoy :D!