Do I choose my wife of 7 yrs or my 15 yr old son??

My wife has told me to choose him or her. He came to live with me from his mother two years ago. He was having some issues with her and we though it may be better with me. He was ok at first but between getting older and hanging out with the wrong people he as gotten worst. I have tried everything from spanking, taking things away, lecture ect. nothing seems to work. He has got in trouble with the law because he got in a fight with his step father at their house and was charged with assault. He has smoked Marijuana with his friends and some things at the house have came up missing. when i question him about it of course he has no idea what happen to it. My wife said she has a 7 yr old daugher (my step daughter) that should not be exposed to all of this so she told me he cannot spend one more night in our house. either he leaves or she will. She wants him to move back with his mother where he was fightng with his step dad in the first place. Him and his mother do not get along at all. Do I send him there were I know he will be unhappy or tell my wife to leave? Tough choice. Right now he is in Juvienile detetention for 6 days for probabtion violation. I hope and pray that six days of being locked up teaches him something. when I pick him up wednesday i am taking him to a rehab where he will get treatment for his substance abuse and hopefully his anger issues. He will be in patient for 90-120 days. Even after all that my wife said she does not want him in our house. not even to visit for a long time. She makes these comments about him all the time about how he is an idiot and it is starting to wear on me...what do I do?????