Every couple of months or so your son or daughter arranges to stay at their partners house, which is in the same town as you so. While they are mostly staying with their boyfriend or girlfriend they completely intend to visit you and spent family time too. To get down there, they have to book a train to the city nearest your home (a 20 mile drive) and there is no mode of transport between this station and your town. They send you a text asking if you can pick them up from the station around 9pm on a work night, but they already have a ride arranged for when they go back.
Do you agree straight away, or do you think they should make their own arrangements?
Totally not hypothetical, I ask my mother to give me this ride once every 3 months or so (and im willing to pay the petrol) so that I can actually visit both her and my boyfriend. Every time she replies telling me how she's not my taxi service and to sort something else out. Kind of upsets me when I never see her and it's the least she can do.