I'd encourage diplomacy too, in spite of my earlier post, I don't know what he's thinking, or what's going on in his head.
If something belongs to me and needs fixed, it might get it sooner, or later, it might sit there until I need it again, whatever, could be a while.
However close your friendship is, he could think you're close enough he treats it like his own, not worth spoiling the day on a misunderstanding
Might try something like "I'm just gonna list it like it is" ? ; )