One step at a time...one at a time. First see what happens when confronted and some time out of the house at his parents or however that works out. Be sure to do what all the others have advised, and maybe come up with a couple/few plans B,C,D and F depending on how each step falls out...
I am sorry you are at this point, be strong!!
T^2
In the depths of winter, I finally learned that within me there lay an invincible summer. - Albert Camus
Uncertainty is the very condition which impels people to unfold their powers.-Eric Fromm