We are always asked at last minute. Since we like to be good neighbours to all, we have never refused.
Half an hour after arriving the heating goes off. No other source of heat in sitting-room. Remote control for tv is clutched by older son and no suggestion that perhaps babysitters would like to choose what to watch.
Sometimes back quite a bit later than has been stated. Never a big box of chocolates or bottle of wine as a thank you.
Problem is: how to stop without causing offence?