Dear Mary: Is my brother being gaslighted by his boss?

Q. My brilliant brother, who graduated last year, could find nowhere to live in London so we were all delighted when he found work as a live-in assistant to an interesting (and successful) employer who works from home. My brother is super-efficient and lovely to have around and I’ve no doubt that he’s made himself invaluable, but I am worried that at the same time he seems to be losing his own self-confidence outside of the job. There are many minor examples which suggest to me that his employer may (perhaps unintentionally) be undermining him — maybe so he can hang on to my brother and ensure he is not poached by either a girlfriend or rival employer. How can I tactfully raise this suggestion with my brother, who is now acting like a cult member? I have only met the employer once and he is rather intimidating.
— Name and address withheld

A. If you act quickly, you can buy tickets for the revival of Patrick Hamilton’s Gaslight at the Playground Theatre in London W10, starring Jemima Murphy as Mrs Manningham. The cast has made a good job of this classic tale of psychological manipulation and, of course, since the charge of ‘gaslighting’ has never been more fashionable, it would also make a good evening out for other readers wishing to tactfully point out to loved ones that they may be suffering from ‘emotional abuse’ by bosses or romantic partners.

Q. A woman I know well insists on my sharing her table at the work café I frequent. She usually talks forcefully and disparagingly about someone or something and I feel depressed by her negativity. I cannot easily change my café, and if I try to sit somewhere else she gets offended and can then be hostile.