Hi Origami,
I'm just now getting caught up. How are things going?
When it comes to boundaries with our d-c's you have to be very specific as they are good at finding "loop holes"
You really might want to consider putting everything in writing and have your son sign it. That way if he doesn't follow through on something he can't claim "you didn't tell me that".
If it were me, I would set a specific time limit on how long they can live there. Give a specific date and have both of them sign this. (hopefully it won't come to this but if you had to evict them this document would be useful)
Something you might consider if you can, you said the wife is paying rent out of her paycheck, you could set this money aside and save it for them. When the move out date comes you could give it back to them to help with getting their own place.
As for the incident of your son locking the wife out of the room, I would remove the lock.
Some food for thought; the more uncomfortable you can make it for them the better as they will not want to stay. If it were me, I would go as far as canceling the cable. I would also disconnect the wifi or change the password.
I know you are concerned for the new wife as you said she is a very sweet girl, but remember, she made her choice, that is on her not on you. There are consequences to the actions we take, good or bad.
My son also married the sweetest girl and he destroyed their marriage. It broke my heart for her but in the end, it made her a much stronger person.
Let us know how things are going.
