Mr Honesty

Everyday I will ask lervin how is his day is school, what he had for recess, did he finish his food etc etc. That's very normal isn't? Just last week, I noticed that 50cents is missing from his coin pouch and so I ask him what did he buy. He hesitate for a moment and I already know he bought smth that he shouldn't. Still he admit to buying a packet of peach tea to drink. He knows that I usually don't allow them to drink. You will never know if he will start coughing anot. If he does, this can goes on for a week plus. But well, since he is being honest to me (with my persistent questioning), I told him he can't buy this drink everyday and I would prefer him drinking water from his bottle. He said ok and I really hope he listen!