Such a small, ridiculous issue to post about but I don't know how to get out of this situation!
For the past year, I have car shared with another family to take my youngest DS and their son to school (about 40 mins away from our home with traffic). It always worked brilliantly and was very easy.
A third family recently moved into our area and asked if they could share too. We said yes. But they have been difficult from the start - dictating which lifts they can and can't do and often letting us down at short notice. A couple of times they have asked to drop their son at my house and then been 20mins or more late, which means we're all late. This morning I turned up to pick up their son, only to be told he was still in bed so they'd take him later - no hint of an apology despite the fact it is out of my way to pick him up.
I obviously need to put a stop to the situation, but will still see them at school functions and the boys are in the same class so don't want to make it awkward for them. How can I end it gracefully?