SS,
Congrats. I have the exact same. I am honest about how I feel or my expectations and then feel bad if its upsets folks.
I agree with all the posts above -- I realise more each day that as long as I am doing the next right thing for me, that is enough.
This all makes me terribly uncomfortable as I am a people pleaser. But trying to make people understand rarely works anyway and tends to knock it up a notch. So now I try to keep my views to myself unless there is a direct impact on me or my kids.
Which gets me to the point. In this case, you were setting boundries about your son. In my case, this would need to be done. And if they dont like it, they will have to respect it and you are the father and if they cant, so be it. You may not convince them, but in my opinion you need to stand your ground.
I relate to this as I have on-going battles with my Ex about my youngest where we have totally different views of what she needs. But here I have no control, but you do.
All the best!