i'll lightly pencil you in
To pencil someone into a schedule but using a light amount of pressure. This way, as you know they will always cancel, when you erase, there is no visual indent of their name in your schedule.
Guy: sorry I keep cancelling on you, would you like to go to the cinema on Friday?
Girl: yes, I'll lightly pencil you in.
Guy cancels
Girl to friend: I am glad I only lightly penciled him in, as there is no indent to remind me that he cancelled AGAIN!
Girl: yes, I'll lightly pencil you in.
Guy cancels
Girl to friend: I am glad I only lightly penciled him in, as there is no indent to remind me that he cancelled AGAIN!