Depends on the officer and how bored he or she is, and whether they actively smoke, are ex-smokers, and how militant they are about it.
My mom for instance is an ex-smoker and anti-smoking fascist.
I'm an ex-cig smoker and current pipe afficiando and started smoking well below the age you're allowed to buy them. I wouldn't look twice at someone obviously underage smoking.
More you try and forbid and control things like that the more illicit and attractive you make them. No kid ever didn't do something they wanted to because some adult told them not to. Bit of a Catch-22, but kids usually do exactly what they've been told not to. Dunno why, just one of those things. Unfortunately, reverse psychology doesn't seem to work and it's just the sort of thing you have to put up with until they're older and making better decisions.