What can you do when you are afraid of your husband's teenage son?
Talk to your husband, tell him the problem. He should do whatever necessary to protect you. If he doesn't move out to somewhere safe. You may need to do that to get his attention. I can almost feel the fact that your husband is either non-confrontational, or he too is a threatening source to you (the apple doesn't fall far from the tree) meaning "like father like son." There is no possible way he can't see or hear what is going on. Take the advice of the above poster, but be sure you plan it out well by packing your things a little at a time and hiding it, finding a good place to live (you can also go to any Abused Women's Center ... call Mental Health for more information) and then make your move. Once you leave, keep going! Good luck!