"It's no good denying it. Mrs Mortimer saw you in the newsagent buying cigarettes. She called me as soon as she got home. You know how nosey she is: she wanted to know whether I allow you to smoke.
So where are they? Where have you hidden them?
Come on, I'm not waiting all day. Hand them over now and you'll get six. If I have to search for them, it'll be twelve. Your choice."