unfortunately, your boundaries are only about you. You can attempt to create and enforce boundaries around your S. Unfortunately, they are not enforceable, as explained in the above thread to some extent.
If your H has any access to your son, even if it is illegal access to your S because there is a restraining order... you actually can not... 100%... enforce a boundary around your S.
Boundaries can only be enforced as in regards to ourselves.
