DEAR ABBY: I am an active 90-year-old grandmother who every year treats my family to a week’s vacation at a beach house. We have a lovely time together.

Two years ago, my grown son, “Robert,” brought his girlfriend, “Gennifer,” and her teenage son, “Jackson.” After the trip I was shocked to hear Jackson had killed the family kittens “to see how it felt.” I was horrified, but knowing he was in therapy, I eventually agreed to allow him to join us on the trip last year.

We are now looking forward to our trip this summer. However, it was recently mentioned that Jackson has been hearing voices instructing him to kill a human. While I am sympathetic to his mental illness, I am extremely frightened for myself and for other family members who are coming. I do not want Jackson to come this year.

I am concerned that if I approach the subject with Robert, he will be upset and I will lose all contact with him. Because he lives out of state, our visits are limited as it is. Please help me, because the trip is in about four weeks.

— SLEEPLESS SEASIDE

DEAR SLEEPLESS: Clearly, Jackson is seriously disturbed. Because you are fearful that you or some other family member could be hurt — or worse — talk to your son about it. That boy’s mother should not take him anywhere without first clearing it with his psychiatrist. You should not be expected to entertain him as a houseguest unless you can be assured that he won’t present a danger to himself or to others.

— ANDREWS MCMEEL