Read your sitch update. Also read Zeus Card Game Theory. Impressive and thought provoking. I need to read it again a few times.
I have seen and been involved in similar situations, provoked by WW totally. No need to give you the detail, they are all horrible, yours, mine, anyone's
You started calm it seems. Get out of those situations quickly it will end up in rapid fire and weapons hot. Both sides ultimately. It's a concious or unconscious game. Probably 'Let's you and him have a fight' (remember Eric Berne?). Don't engage, the games are always rigged and at best you walk away with a small bruise. At worst, devastating things can happen. Don't forget a single word can destroy everything you have worked hard at.
Please stay away from any communication and contact for a while. You both need to get space for definite. If your S sees this kind of integration at this age it could harm him. I spent such a long time protecting my children from my WWs spew. It is so, so, so important they don't get expose. It will also damage you.
There is never any victory in wars of this kid.
I don't mean to lecture, sorry if I come across this way, I mean to help - from my experience and from knowing how best to handle this - validate if you can, otherwise, say nothing at all and get out of the way - even if he comes into your room and start flailing away at you. Don't forget his questions are loaded right now. There is no right answer, it's a trap. Don't walk into it, just don't answer.
His resentment is running high. You must be careful.
Surfer.
M46/W40/D8/S6/T20/M12/Separated 6/2016,W takes kids Issues2009 Wpartying w/g.f's2013on EA2013PAdeniedWleavesMBR ImeetAP/EAhalts VariousBDDates MFCourse WSpew EAresumes I halt Wrages DBIng4/2016