I think it was a lifetime movie, not really sure.  The plot was about a boy who has an affair with his father’s girlfriend (his stepmother).  The affair goes on and on during the movie and at the end the woman and the son plan out the murder of the father so that they can keep their thing going.  I can’t remember if the father finds out about the affair, I think he does.  They live in some kind of mansion I think out in the woods.

I think at some point during the movie the woman and the son have some kind of argument and try to kill each other or something, but at the end I’m almost sure they ended up together.

Anyways, I cant remember the tittle of the movie at all. Please help!