He needs to be out on his own. Get newspapers and start looking for him a place to move to and tell him you will help him get moved out and then he is on his own.

I survived 4 of those teens. We helped them get started somewhere else and then slowly took them off the respirator.

You and your wife need to have a serious discussion about "ground rules". Give your SS rules that he MUST obey, otherwise he can't live there. You and your wife need to be on the absolute same page about these rules and both be able to defend them. Although in your case I would suggest she be the one to first tell him about the rules. Put everything in writing.

Also, talk to your wife about giving him until he is 21 to start charging rent. He won't want to stay home so bad if he has to pay for it!

I wouldn't fight with your wife too much about his attitude. You won't be able to change it through force and it will only cause you problems with your wife. Lay the ground rules, and as long as he follows these, ignore him unless he chooses to be human towards you.

He's a big boy and needs rules if he's going to live in your home. I have a son,he's only 7 but rules are rules no matter what the age. If he is choosing to live in a home, he needs to respect the other occupants and respect the surroundings. I like what astra said about giving him til 21 then charging rent.
I often think about what would happen if my son needed to live with us when he's that age...I can tell you I'm harder on him than anyone so there would be a printed sheet of rules posted DIRECTLY on the fridge. If they don't like it...then leave. Until he starts paying the mortgage and expenses in your house he must follow the rules. You wife is being a typical mother and protecting her baby even though he's not a baby anymore. She obviously sees you as a threat to her relationship with her 'child' and that's why she's on the defense. most parents hate being told negative things about their childs behavior. I see my son in a most realistic light but even I slip up when a teacher comments about something bad he did and i'll think,"you're picking on him." BUT then reality hits me and I have to face the facts about his behavior and stop painting him as the victim. You won't get anywhere with your wife until she starts viewing her son as a man and stops viewing him as the victim who needs protection from you.

Seems like it would benefit you to take a very laid back approach when dealing with her...put it on yourself if you have to just to get her off defense so she can really hear what you're trying to tell her instead of thinking, "he's attacking my son, he doesn't like my son...etc" Then once she's off the defense, she'll be more open to setting firm rules for her 'child'.

~Dignity and Grace. Be that and sneak past the hate...wrinkle free~

I think whether you let him live there for nothing depends on your daughter's ages and what rules you have placed for them. Rememeber rules for your daughters can't be any different than for your wife's son.

My brother who lives in Australia has the same problem he has 2 older step children and they have one bio daughter. One of the older ones make him feel like he is he outsider and did not speak to him. We went over to visit in March and observed what he was talking about.
I know he is my brother and I love him very much but, I noticed he made himself the outsider.
He had got so used to feeling that the grown children did not talk to him that it became natural. So, I told him to make the first move to say hi, or how was your day say anything to make them respond. After much debate he agreed to try this and it really made a difference even though they still have rough days. You can not be the outsider in your own home.

On the flip side my FH says the same thing about my 16yr old son. Honestly what 16yr old talks to their parents..lol
I explained to my FH he does not talk to me either except when I make him. So I insisted that my FH say something to him each time he came in and if my son was rude or did not answer I brought it to my sons attention. Of course we still have rough days but, it really has been better than it was.

Our biggest obstacle was realizing we as adults were making ourselves the outsiders and letting hormones of a child get the better of us.

Hopefully this may help you.

was your wife a single mom to this boy? there's an extra layer to the complexity, speaking from my own past single-mom experience. How to navigate an established "agreement" of boundaries or rules is unchartered territory for the newest member, unfortunately. I have a better appreciation now for my husband's challenges with my daughter (he moved in when she was just turning 16) and even at 21, there still lingering bits of her presumed authority over our relationship.

Focus on what is strongest between the two of you. Tending your foundation now will last far longer than the son's temporary parking spot.

I have to also think there may be some territorial dispute - even unspoken. My (almost) 19 year old stepson fancies himself the man of the house. Mind you, he works part time (12-20 hours) and spends the rest of his time online gaming. We had one big blow out where it was pointed out he was not my equal, not the man of the house, and not the one in charge of the younger kids - especially my bio son.

Tension? You can cut it with a knife. ANd the fact he gets away with everything and his mother says nothing makes me resent both him and her. So I am not looking to extend an olive branch.

It could be this display is his way of saying he doesnt respoect you - acknowledge you. You may hvae married mom, but aint nothing to me. If she raised him alone, he may also see you as the one who is going to ruin his good thing by tlling his mom ENOUGH!

Just some thought based solely on MY experience. None of us can get in his head.

AWB