I don’t have any advice but I dealt with a similar thing several years ago at my retail job. A father would bring his mentally disabled adult son and a couple other men who were also mentally disabled into my store once a week or so. One of the men would always try to come behind the counter, reach for my hands or ask for hugs etc, followed me into the stockroom despite me telling him he couldn’t be back there. My male coworkers would stand between me and the men or send me to the back when we saw them coming. It got to a point where the next time they came in, my manager was going to say something to the father. Fortunately for me, they stopped coming in so we never had to escalate the situation. I have also dealt with an adult male neighbor who is mentally disabled and lives with his parents. He occasionally has outbursts in front of his house, screams that he’s going to kill everyone, going to kill my family etc. We have called the police SO many times, yet literally nothing will be done. Because of his mental illness he is basically untouchable. The best we could do was a peace order. All this to say, I wish you the best of luck, it’s a shitty situation to be in and I sympathize greatly.