I want to put up a sign inside (not outside like in the pavement) a supermarket with 'no loitering' on it; by this I'd like to mean if you don't want to buy anything, don't come inside and flirt with your girlfriend, joke around, pace around the supermarket like you're waiting for someone to show up etc. Is it the right sign language to use inside a supermarket?
I'm not sure about this because I've seen this sign in public places mostly in crime-ridden areas. If it's not right or a bit offensive, what do you suggest?