You know your friends. You know you get along in all situations. But if you're considering going on holiday together - and you haven't before - there are questions that must be asked (if not directly put to them, than at least run by each other). For example:
1. Are your kids compatible?
Not do their children get on with yours - that would be a bonus, obviously - but are you parenting on the same page re important things such as whether they get to order anything in the beach restaurant besides chips. (It's tricky if one set of youth is living like the Middletons while the others are on Tiny Tim rules).
2. Are you compatible when it comes to food?
Are you all getting up at dawn to go to the fish market or are some of you more "let's nip to the shop for vacuum-packed tortilla chips and Coco Pops".
Also (and this is a mid-life issue) are you cooking compatible? In my experience, holidays at this stage can get quite competitive in the kitchen, as in "Oh! I wouldn't put that in a salad nicoise" or "Can I not have the marinade, if that's how you're doing it".
3. Are they over-orderers?
Are they the sort who want all the fish specials, and double up on the tapas, and then you can't eat half of it. (To be fair, you lost your appetite seeing the price of the sea bass).
4. Are they active?
Are they swimmers? Gymmers? Non-movers? Each to their own but these groups do not mix.
5. Politics - where do they stand?
No one ever took politics on holiday until last year; now it's all you'll talk about - and it will get heated, even if you're in agreement. Someone will say "what people don't understand..." and you're off.
Best to check you're on the same side first.
6. In what circumstances do they put the TV on?
In the event of bad news? A World Cup qualifier?
And while we're on the subject: what are your technology rules? These days, the most unlikely people turn up on holiday with their iPads and never put them away, their excuse being "work" or "builders" or "sorting out the kids."
7. What are their tastes in music?
I'm not being funny but other peoples' musical taste can get quite "nails on blackboard", and there's also the issue of when they like to crank it up. Some people - often the quiet ones - like Firework during breakfast and That's What I Call Acid House for sunbathing. Or their children do, and they have never yet in living memory said no to their children. (See, are your kids compatible.)
Other things to watch for
They never come equipped, so they will definitely not bring enough sun cream (more of an issue since you have switched to the hypoallergenic one that costs $10 a squirt). Their marriage may be on the rocks. A couple of you have recently discovered bridge. Or twitching. Or cycling. They have really good friends on a family holiday just down the road, who don't have a pool. One of your children may have a really bad crush on one of their children.
There you go. It'll probably all be fine.
This is an edited version of an article which first appeared on The Telegraph, London.