Dear Mary: what should I do if a fellow passenger is reading porn?

Q. On a recent short-haul flight, I had the misfortune to be seated next to a much older man who read, for the entirety of the flight, an erotic novel on his Kindle. I tried to avert my eyes but the bright screen and lewd language kept catching my eye. I was stunned into silence for the 1.5 hours I was trapped next to him. Should I have said something, and if so, what? – L.R.B., Bristol A. Certain bridge players complain they can see others’ cards – and no doubt they can, but they don’t have to. Equally, lewd language on a next-door Kindle can only be seen with

Dear Mary: how can I help pay for an expensive lunch without seeming rude?

Q. My husband and I (both in our eighties) recently visited a carpet shop with a view to replacing the stair carpet in our four-storey house. The salesman showed us various carpets and we discussed their relative merits. When I asked him how hard-wearing a particular carpet was, he looked at us carefully and said: ‘Well, it is not going to need to be very long-lasting is it?’ We were a bit surprised and will be taking our business elsewhere. But can you suggest how we might have been able to indicate to him politely that this particular form of words was unlikely to secure a sale? – R.H., Cheltenham

Dear Mary: how can I get restaurants to turn off loud music?

Q. My husband never wants to go out to lunch on a day when he could be gardening but he has grudgingly accepted a wonderful forthcoming local event that I’m very keen to attend myself. Now I find from a fellow guest that our host is planning on seating him next to a woman who (she says) is ‘one of his biggest fans’. The feeling is not mutual – in fact, if my husband found out about this seating plan, he would definitely refuse to come. Yet now that I know about this, it would be disloyal and deceitful of me not to tell him. How can I resolve this

Dear Mary: should I encourage guests to strip their beds? 

Q. Our son, 17, who is generally a credit to us, has started eating with his mouth open. It’s the only thing we don’t love about him. It’s not to do with sinuses and we don’t know if it’s a peer-pressure thing, but when we beg him to stop he always just laughs and insists that: ‘Eating with your mouth shut isn’t a thing any more.’ We are fretting because we have some very fastidious Americans coming to lunch who are important potential clients (and snobs). They are bringing their daughter, also 17, and have specifically asked that our son be there too. Help.  – Name and address withheld A.

Dear Mary: how do I politely ditch my hairdresser?

Q. I have just returned from a holiday where I was the guest of someone extremely rich. She was emphatic that everything would be covered and I must not even think of bringing a present. However, after one lunch in a restaurant, I felt driven to make a gesture and quietly asked the waiter for the bill. The sum involved was the equivalent of two months’ rent for me, but worse, no one noticed I had paid.  When the time came, everyone just got up to leave and I realised our host has an account with the restaurant, so she would not have noticed either. How, without being vulgar, can

Dear Mary: how do I stop a nosy acquaintance from snooping in my house?

Q. I’m very fond of a neighbour in our village and we see a lot of each other. She has told me she has got X, an acquaintance of mine, coming to stay and wants to bring her over for a drink before lunch on the Sunday. The trouble is X is a decorator and will ask if she can look around the house. I happen to know that she’s very nosy and indiscreet – but how can I say no? – Name and address withheld A. Why not pretend to be enthusiastic about the visit and then, on the day before, ring to say you are longing to see

Dear Mary: Is it rude for guests to ask for my wifi code?

Q. Do you agree with me that it is very bad manners to ask for a wifi code as soon as you walk into a lunch in someone else’s house? I have a centrally located, although cramped, flat in Soho and am very happy to cook for friends and friends of friends, but it is a tough act to pull off single-handedly and it throws me when people ask for the wifi code as if supplying this is no more time-consuming than telling them where the loo is. Moreover, surely you should not even think of checking your emails and WhatsApps when invited to a non-professional lunch? – P.R., London

Dear Mary: how do I make sure I look popular at a book signing?

Q. A central London bookshop has kindly invited me to be one of 30 authors signing copies of our books at its Christmas customer evening. I feel it would be rude to say no, so I’ve said yes. But I went to last year’s event at that same shop, and saw the excruciating sight of some of my favourite authors sitting alone and unvisited at their signing tables, while crowds were queueing round the shop for Gyles Brandreth. This would bring back my worst childhood nightmares of not being picked for games teams. What occupation could you recommend to pass the time as I sit there from six till eight,

Dear Mary: How can I stop dinner guests squabbling about politics?

Q. How can I prevent my guests from arguing over politics at the dinner table? I have been working abroad for far too long so have taken a house in London next month to give a few dinners to catch up with friends. To one of these I want to invite two couples in particular. Both are good friends of mine, although they have never met each other. I know they would get on extremely well and probably even work together as they are in the same fields – but they have very different politics and are bound to start discussing these as soon as they walk through the door.