This is why friends shouldn’t let friends drive drunk.

New Jersey cops scored a drunk-driving hat trick when they busted a motorist for DUI, then pinched her two sloshed friends who separately drove to the police station to pick her up.

It all started when a cop in Readington Township pulled over Carmen Reategui, 34, after he noticed her car swerving on Route 22 early one morning last week.

Charged with DUI, she was taken to the town’s police station, where she called a friend to come and get her.

But the friend wasn’t much help.

Nina Petracca, 23, who drove down to the station, was filling out necessary paperwork when a cop noticed that she, too, seemed a little tipsy.

She failed a sobriety test right in the station lobby and was charged with DUI.

So Petracca, too, was slapped with a DUI charge, as well as a drug charge for Vicodin tablets found in her purse, police said. Both women then reached out to another friend, Ryan Hogan, who, like Petracca before him, raced down to the police station to help his friends out of a jam.

But when he showed up, Police Sgt. Carlos Ferreiro thought he seemed off.

“When I was outside talking to him he displayed signs of intoxication,” he said.

Hogan also failed sobriety tests, police said.

“They finally got a sober adult to come pick up all three of them,” Ferreiro said.

“It’s the first time in nine years I’ve had something like this.”

All three friends are scheduled to appear in court next month.

Reategui vented about the ordeal on Facebook.

“Just getting home,” she posted to her page on Dec. 16. “ABSOLUTELY THE WORST NIGHT OF MY F–KING LIFE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!”

Petracca “liked” her lockup pal’s comment.

Later in the day she was wishing the whole thing had never happened, posting:

“Heavy, heavy heart. Wish there was an undo button in life.”