Two Sundays ago, I picked up my nine-year-old daughter from a girly girl sleepover birthday party at her friend Jo-Jo’s, five minutes from our house. In addition to her rumpled pink sleeping bag, my daughter left the host’s front door carrying a purple balloon and a goodie bag filled with unicorn stickers.

Before we got home, her eyes welled with tears.

“Mom, you won’t believe it,” she said, the tears slipping down her cheeks. I thought of pulling the car over to the side of the road. Had she witnessed a kitten being tortured?

“Jo-Jo’s dad was… SMOKING.”

Long parental pause. I kept driving. How to proceed?

“Cigarettes?” was the first question I ventured, my voice shaky. My 70s mind immediately conjured marijuana, crack, an orgy of drugs and sex with wide-eyed nine year old witnesses…

“Yes, cigarettes!” my daughter said in a tone of outrage and disapproval more commonly associated with heroin addiction funded by street prostitution.

“Jo-Jo caught him. He said he was really sorry but he’s a little bit addictive. She says he’s going to die.”

More tears flooded the backseat. TEARS! Triggered by a friend’s 40-year-old father puffing a Marlboro on his back porch? For heaven’s sake, even President Obama sneaks a cig here and there!

Then I realized: in nine years of life on this planet, my daughter has never seen a live human being smoke a cigarette. How utterly amazing. By the time I was her age, I had already smoked my first cigarette. I had also drunk an entire plastic cup of beer from a keg at a touch-football game and gulped a huge disgusting sip of a martini while cleaning up after one of my parents’ frequent cocktail parties.

With the fog of social stigma and legal repercussions having firmly attached itself to cigarette smoking and even the most genteel drunken debauchery, the casual adult vices many of us grew up witnessing have vanished from the world of many American children.

None of my friends smoke any longer (okay, one does…but that’s top secret). My husband and I have beer and liquor in our house for guests, but we never booze it up ourselves. The results of my own experimentation, plus evidence collected from myriad out-of-control adults, convinced me early in life (long before I had kids) that alcohol, cigarettes and drugs were indulgences I couldn’t afford . Our friends and family members rarely drink more than a glass of wine at dinner. Our children have never witnessed firsthand any adults getting intoxicated, passing out on the toilet, or throwing up in the front yard (things I took for granted by the time I was nine).

What a refreshing change.

But it leaves parents with a small problem: how do we reality-check our children when it comes to vices such as smoking and drinking? How do you explain to a child that although drinking alcohol and smoking cigarettes CAN kill you, they are harmless in small doses? Should we even bother? Maybe it’s wiser to let them grow up thinking erroneously that one cigarette can be deadly, or that one glass of beer at dinner means you are an alcoholic. A little scared-straight before they even are of the age to experiment. Hey, why not?

Well, there’s that trust issue. I’d like my children to turn to me as a source of reliable information, especially when it comes to alcohol, sex and drugs. So I need to be truthful now, in age-appropriate doses, in order to be a faithful source in the future when it really matters. Plus, although alcohol and cigarette usage have declined among American kids and teenagers, they still present risks to our children and their friends. My children will, in childhood and adolescence, have peers who drink, take drugs and smoke cigarettes.

National Institute on Drug Abuse data shows that 29% of 10th graders surveyed in 2010 had consumed alcohol in the past month; over 12% of high school seniors smoke cigarettes. Neither I nor my kids can bury our heads in the sand and pretend that addictive vices have been eradicated from the face of the earth, even though we live in a far more sanitized world today.

So a few days later, during an atypically colossal party my husband and I hosted for a local charity, there was one guest among 250 who got blasted. My three kids, ages 14, 12 and 9, were all working the party, taking umbrellas and giving tours of the basement. The boorish drunken stranger poured beer on his loafers and our dining room rug. He put his hands in inappropriate places on other female guests’ bodies. He locked himself in the powder room and proceeded to snore. My husband whispered: “Get the kids upstairs so I can get him out of here.”

Instead, like an evolutionary anthropologist pointing out a rare fossil, I made the kids watch. “There’s an alcoholic,” I told them. Who knows? It might be their only chance to see one.