pencil you in
To tentatively make an appointment or commitment. Implies it could be changed or canceled, since pencil marks are erasable.
Bob: "I got tickets to Saturday's game. You want to go?"
Tom: "If I can. I might have to work that day, but I'll pencil you in."
Tom: "If I can. I might have to work that day, but I'll pencil you in."
pencil you in by Aaron of Minneapolis May 10, 2010
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