Tomorrow 2 friends and I are going on an organised 16 mile walk, about a 45 minute drive away. My husband is also doing this walk, but he could potentially add another loop of 9 miles run/walk. My friend is driving and of course he could have a lift if he was definitely just doing the 16 miles (it would mean a long wait for him as he is faster than us). However, if he decides to do the extra 9 we could end up waiting for him. There is also food at the end of the event, which I know he will want.
If it was just the 2 of us doing this, of course, I would wait around for him. But I think it is unreasonable to expect my friends to wait about for him.