Parents teach their children — don’t take candy from strangers.

Flash forward to the Club Car in Nantucket — that “candy” was whiskey and the stranger was Kevin Spacey — a creepy Hollywood actor with an alleged history of predation.

Heather Unruh’s son, 18 at the time of the alleged assault, made several rookie mistakes the night in question and this is precisely why teenagers don’t belong in bars. They don’t have the life experience or maturity necessary to understand the unwritten rules of the bar scene.

The first being, if someone offers to buy you a drink you’re still in platonic “friend” territory. But — and there’s a big but here — if a man offers to buy you more than one drink, or several as Spacey did, he is sending you a strong signal he’s romantically interested. After all, adults know there’s no free lunch so if someone is shelling out their money to buy you drinks, there’s a reason: They’re into you. The other unwritten bar rule is if a person accepts more than one drink from another they’re sending the signal back that they’re also potentially interested on a romantic level because the unspoken understanding is if the drinking duo were just friends — they’d be splitting the tab.

I’ve been to plenty of bars in my day, including the Club Car as recently as last month for its annual Christmas stroll celebration. I can tell you that I don’t accept a man buying me more than one drink because I don’t want to lead them on. This is the first rookie mistake by Unruh’s kid, who didn’t belong in the bar in the first place. He also failed to question why a decades-older TV star like Spacey estimated to be worth around $100 million would want to hang out with him all night.

The street-smart among us know that a) bars are pick-up joints; b) when adults drink they flirt and hit on other adults. And c) they often get handsy — especially as the night progresses.

Notwithstanding, as a mother of teenagers myself I can understand how a youngster could become star-struck and blind to all of the above. Many naive teens don’t have the life experience to know how weird and unstable many celebrities are and that boatloads in Tinseltown suffer from a grab bag of demons that unsuspecting teenagers would be wise to stay away from.

That said, I commend the Unruh family for courageously bringing this issue to light. Innocuous touching in a bar is widely accepted — but groping without consent is not. If the allegations prove true, Spacey should be held accountable and not given special treatment not afforded to the masses.

Sending a hug to the Unruh family. Mistakes made are lessons learned.

Adriana Cohen is a nationally syndicated columnist, Herald Radio host and TV commentator. Go to adrianacohen.com.