Cancelling a sample lesson?

So I had sample lessons scheduled at 2 schools for this month to decide, and I think I know where I’m going, yet I have a lesson scheduled with a professor at a school I have decided not to go to. I need to cancel the lesson. When I email him, should I be honest and say I’m canceling because I have already decided where I’m going? Or how to word that? I don’t want to lie and say “something came up” at school and I can’t come, and then if he offers to reschedule, that wouldn’t work.

Just let him know you have made your decision on a school and thank him for his willingness to give you a sample lesson.

Yes, they are used to situations like this and won’t hold it against you.