A Good Friend

of mine will be in town this week and wants to go to the casino. He is not a counter. Should I tell him that I can count cards and help him, or should I keep quiet and let him play on his own? My wife and another trusted friend are the only people I have discussed my abilities with. He can be trusted to not say a word, but I do worry about him no longer looking like a ploppy if he is asking me for advice or waiting to place his wager only after I place mine. Has anyone else ever been in this situation?