If the boy is a minor, no you can not. If you want to maintain a relationship with your wife, I would suggest that before you take such an action that you have a long honest talk with your wife. Don't just throw the kid out without discussing this with your wife. Such an action could put a irreparable strain on your marriage. I do not know the circumstances of the discord between you and your stepson but you must remember that a Mother loves her child unconditionally. She may hate his actions but she still loves the child.