How many times do you let them come back?

My wife and I never seem to see eye to eye on most situations but this one I will have no problem putting my foot down to. Her youngest son, now 26 or 27 years old has been dating / messing around with / sleeping with this girl for a few years now and their relationship is not the best. They get along for a few months then all hell breaks loose. They make up, get back together and then within a few months they're at each other's throats again. Earlier this year it got to the point to where he found himself in jail over a bunch of mess she put him through and he had to wear an ankle monitoring device and have to move back in with us due to a restraining order that was placed on him by her. That lasted all of a few weeks until they made up and started hanging out again.

This is how ig'nant (ignorant) the situation became. My step son loves smoking weed. All day, everyday. One house rule I told him during his ankle monitoring stage was I didn't want to smelt weed inside my / our house. One day I was working in our bedroom and he and his girlfriend came to the house and he reeked of weed so back until the smell made its way through the house and into our bedroom. I put him and her out at that point. He began sleeping in his car in our driveway, because of the ankle device he had to be at our house by a certain time. A few days later we were hit with a major snow storm and that sunday morning the wife said to me "we need to let them come in and get warm." I said "them who?" She said her son and is gf. Yep, her dumb tail spent the night with him in the car knowing it was going to snow that night instead of her just going back to her warm apartment.

Ok, he's still in court over those charges. 2 of them were dropped because she didn't show up but he still has one he's facing. The took the ankle device off a few months ago and he made a bee line straight back to their apartment.
He's been there ever since. About a week or so ago my wife made the comment of him wanting to move back home with us because they were at it again. I told her under no circumstances would he be coming back to this house. She said that they were arguing and she was trying to get him back into trouble and I told her that was not my concern. Everyone in the family has been telling him to stay away from her and leave her alone but he keeps running back to her every chance he gets only to get back into the same mess as before. Now the wife is adamant about "this is my child and I will not see him out on the streets." My reply was, "yeah, I know he is your child but if you keep running to his defense every time he calls then he's never going to grow up and figure stuff out for himself." I also told her that we do not have a revolving door on our house so they can come and go as they please.

Last night I had to run to my daughter's apartment to help her with something and when I got home my wife said to me that she had to run and take her son to get a hotel room for the night. She left and came back a few hours later. This morning she walks into the bedroom to ask me about filing harassment charges against someone. I asked her what now and she said that the gf had been calling and texting her all morning. I told her to just block the number. She said she did but the girl would hit her up from another number. I told her first of all it takes all of two or three clicks on your phone to block a number. Eventually she'll run out of numbers to call or text you from. She told me that in the past 2 weeks or so this girl has called or text her 2 or 3 times. I told her that no cop, lawyer, or judge would even consider a harassment case for 2 or 3 calls or texts.

Then she made mention of her son coming back to your place and I told her no. Then she got all angry. I told her that if she stayed out of their business and let him figure out his own life he'd grow up and stop dealing with her. My step son is the type of person who has to have a woman under him at all times. He's not happy being single. My wife said that now that he's in the hotel room his mental stability is so much better. Ok, I'm going to take a beating on this but there are people who have real, legitimate mental issues that they deal with. I do not see that breaking up, again, with a girl you keep going back it rises to the level of your mental stability. If you keep going back they you are doing it to yourself. Something just hit me. My step son has a car so why did his mom have to take him to get a hotel room? I know why . . . because she paid for it. He drives, has a bank account with his own bank card, and he works making food deliveries. Again, why did my wife have to go with him? Because he didn't have any money to pay for the room himself.

Bottom line, how many times do you let your kids keep running back home after you have told them time and time again to leave the situation? He's already been back a few times and has left to go back with the gf. I have no problem telling these kids no when I want them to figure things out for themselves. That's how you learn and grow. My wife is of the mindset that "that's my child and I will not see him out on the streets." I do not want to get into a situation like my parents are in right now. My twin brother (53 yrs old) is now back at home with them along with his grown son sleeping on their sofa because he can't figure his life out. 2 failed marriages, got evicted from their last apartment and just can't seem to get it together. My mom told me last week that if he ever leaves she promises that he will never be allowed to come stay there again. She and the other siblings gave him 2 or 3 months to get his stuff together. That was at the end of March. When his deadline was coming up he wrote this very long text to one of our sisters saying how he feels bad about how his life has gone and how he feels no one is supporting him. He doesn't know what he's going to do but since his deadline was coming up he feels like leaving and never coming back. Our mom felt sorry for him thinking he may harm himself . He's been there ever since with no plans to leave.

Am I wrong here? No, I will definitely put my foot down to my wife and say if she allows her son to come back I will be leaving. I'm just of the mindset that if you don't let them figure things out they will never learn to do anything for themselves. I'm a tough love kind of person.