I was undermined by my fil, mil and grand-mil for many years but did not know. Only my mil is still alive and although she is mostly OK with me I find it hard to forget how nasty they all were about me behind my back and my naivety in not noticing. I never knowingly did anything to upset them (apart from marrying my OH) and even today will do my "duty" in making sure mil is ok and seeing her every week. She lives nearby and I would see her every day if things were different.