Repeat A: Why are you cutting into the wall? B: I bought a new air conditioning unit. A: I don't think that's how you install it! B: Have you ever installed one before? A: No, but that still looks wrong. B: I think I know what I'm doing. A: I see water pipes behind that wall. B: I don't think that's good for the air conditioner. A: I don't think so, either. B: Will you call some professionals now? A: I guess that's the best thing to do. B: You should have done so from the beginning!