Be prepared for more 'tests' from W for she will use every angle to regain control even if it means bringing S into the convo. Just simply say, "I am sorry but your concern about S is seriously misplaced for if you were truly concerned, you would not be having an A at all. As for the so-called emotional affair, it is still very disrespectful to me and our M. Let me be clear about one thing: I will not lie or cover up your A to son. It's on you and I prefer that you stay out of the MBR. We have some decisons to make here." Then walk away.
Why don't you got out tonight. Go to the local pub or a comedy joint. Dress in nice casual clothes and put on cologne. If W asks where you're going, just say "I'm not sure yet...I want to go out. Bye."Be home late line around 11 pm and not fall for W's frantic texts.