Originally Posted by
Mad4Chaos 
She'll feel he'll relapse because we tossed him out.
He has relapsed under your nose and roof.
Your wife has the common and mistaken belief that what you do or say is going to keep him sober or cause him to relapse. She is not that powerful. None of us are.
You have given him the gift of opportunity to learn some recovery tools. You can lead a horse to water and all that. What you son does or the wife frets about is beyond your control. Have you considered attending some Alanon meetings either with your wife or solo? You have your own recovery tools and it's time to dust them off and use them to protect your own sobriety, the only thing you control.
Right now, it sounds like your healthy boundary is that you will not have users/thiefs living in your home. . He's in his 20's and it's likely time for him to take responsibility for himself and leave the family nest, regardless of the relapse.