A weekly series on etiquette for modern living: 8 Staying with friends

1 Don't take a vague invitation for a firm arrangement: You may be under the mistaken impression, as you book your tickets, that you were invited to stay at your friends' villa in Spain/France/Portugal/Italy. The person who says, "You must come and stay sometime" often forgets to add, "In about ten years when we've got the plumbing working".

2 Give notice of your arrival: You may need a safe haven, but it is rude to visit at short notice when you are being followed by paparazzi/police/insane ex-lover.

3 If you are single, do not bring a new lover along unless specifically asked to do so: You have either been assigned the living room sofa or picked to babysit/cook/balance out the numbers.

4 Don't have noisy sex: It only makes everyone else jealous and grumpy.

5 Go to bed when your hosts do: No one likes having to stay up too late to mind a rowdy or morose guest.

6 Do not, under any circumstances, complain, no matter how desperate the situation: When asked, "Did you sleep well?", do not say, "I would have, if only I could have stopped the itching" or "Your house seemed so much bigger in the photographs!"

7 Hear nothing, see nothing: Do not ask, in a quiet moment, "Do you and Bob argue often?" or "Do your children know the meaning of the word 'no'?"

8 Help in the kitchen but do not take charge: Control freaks with obsessive urges to clean, organise, redecorate or prepare the "perfect" organic gazpacho should book an understaffed hotel.

9 Do not flaunt your stunning body unless you are on holiday with equally gorgeous people: Living in a bikini or wraparound towel will make your hosts feel pale, fat and insignificant.

10 Have a life: Hanging like a limpet onto your host 24 hours a day expecting to be entertained is a guarantee that you will never be invited back.

11 Pay for more than your share of food: Don't eat the last of anything. Use your own toiletries. Wear your own clothes. Do not ask to borrow money. That's what staying at your parents' house is for.

12 Do not overstay your welcome: Three nights is the most that your average host can bear - three weeks is pushing it.