It's expected that you'll be mindful of a friend's schedule.
Frank often gives his friend Fiona a ride to work every day, and today has a bunch of errands to do in addition to taking her to work.
Frank wants to finish his errands.
Frank decides to wait to run his errands until after he's dropped Fiona off.
Frank decides it'd be most efficient if he did some of his errands on the way to taking Fiona to work.
Fiona appreciates Frank's consideration and thanks him for the ride.
Fiona ends up being very late to work and her boss is furious with her.