My fantastic BIL and SIL are taking ds away with their two kids for a week. The accommodation is paid for by the PILs (who are going too) but Bil and Sil will be taking ds out and about. Obviously I want to give them some money so they're not too out of pocket for trips etc. Equally obviously I will ask them, but knowing them they will absolutely refuse to name an amount ('oh you don't need to... oh whatever you think') and may also be a bit upset if I produce a massively low estimate! I'd really like to know what you would regard as reasonable for this. TIA