I sometimes send my kids on a "secret mission". The mission to get me a beer without their mom seeing them. It doesn't really matter if she sees of course, just something to do for laughs. Recently, my daughter (almost 12) has grown tired of the game and sometimes tells me to get it myself. My son still goes on secret missions once a week or so.
Life is what you make of it, I think hiding something from your children keeps things a mystery. And sooner or later they will discover it themselves anyway. (be it alcohol, sex, drugs, whatever... ). I would rather be honest with them, educate them and teach them to make good choices and be responsible than try to hide things from them. I view raising my children as my job is to give them tools necessary to survive in life. Those tools include being able to make good choices, and to do that they need to learn and have self confidence. That's not achieved by trying to hide things from them.