My SO’s in-laws (my FOO) did the isolating thing to me. They knew he was helping me with my boundaries and learning to tell them no, and they despised it. So their solution - that I was far too slow to pick up on - was for me to talk to them myself. Cut him out. “Since it bothered him so much”. Like a dummy I fell for it and they would rip me to shreds in private.

They’re pushing your boundaries. You say both of you together so they cut both out and lovebomb the kids. And later they’ll can tell the kids that meanie panini mommy and daddy won’t let loving grandparents talk to the kids and they ‘just don’t understand what they could possibly have done wrong’ and lo and behold gradually worm their way in they way and suddenly you’re the bad guy on all fronts.

Boundaries. They will try and burn them at every chance you get like a tantruming toddler. And if they can’t burn them, they'll read the small print looking for loopholes.