I am looking for a movie where this guy kills his father by poisoning his smoothie ...?

Please I need the title.

The lead character a blond, to me he looks like Oliver from Smallville - Justin Hartley, but I searched Justin's work on IMDB and I did not see a movie that this could be - maybe it is him though.

It was a made-for-T.V. movie and his father had this girlfriend who was also a suspect, but he was using his father's girlfriend's attraction to him to frame her.

At one point in the movie you don't know who killed the father, whose character name I remember was Mason - sorry that is the only character name I remember and I am not sure if that was the father's name.

Also I think the father's girlfriend had red hair.

At the end you find out that the son and his original girlfriend were in on the whole thing and they get away scott-free. Also they show how the son put something in his father's smoothie, which subsequently killed him.

Thanks ALL MOVIE CONTRIBUTORS!