Anonymous wrote:He sounds more mentally ill than in a cult. The New Age thing in combination with everything else sounds less like a life philosophy and more like a delusion.
If he is mentally ill and undiagnosed and untreated then he is likely quite volatile and unpredictable. That doesn't make him a beast that makes him sick.
I would tell MIL flat out you aren't comfortable having the kids around him when he is so unwell and unstable. Point out the illness factors. I wouldn't talk about the cult aspect - stay factual about how he is unpredictable and volatile and unstable. Frame it as illness not as a personal attack on his character or on hers for enabling him.
+1
I would stay in a hotel and visit the people you want. Schedule a time for ILs when BIL won't be there. If they refuse, send your regrets, but your children's safety comes first. If they are going to be jerks about it, there's nothing you can do. Just don't put them or yourself at risk. I'm all for compromise, not bending over backwards or being a doormat.