Senior Week in Ocean City: How heinously are your kids behaving?

They had a plan:

“None of this drink-drink and pass out right away,” said the kid with the trucker cap askew and the lollipop-stick legs.

“Yeah,” agreed his even lankier sidekick. “So what do we do?”

I was dodging herds of bikini babes and packs of panting young men to keep eavesdropping on the pair.

Lollipop was excited. “Long, sustained drinking. Sustained. We just keep drinking and drinking.” He took a swill of his Cherry Coke.

This was zero hour in a rite of passage for thousands of high school seniors: the month-long bacchanal in Ocean City known as Senior Week. And these two characters were on the ground early, making their plan. And Cherry Coke wasn’t part of it.

Senior Week is a tradition that has been dreaded by Washington area parents for decades. It’s the annual migration of newly graduated, newly liberated, barely legal teens to the shore, where they party, plot, puke, hook up, scheme, swim, roam, dirty dance in foam and — for about 10 percent of them — get locked up for everything from underage drinking to drug possession to assault.

For the kids, it’s a week-long dress rehearsal for college frat parties. For their mothers and fathers, it amounts to a parenting final exam.

“Do I let them go to Beach Week?” is the senior parent anthem sung for months beforehand. On discussion boards, at PTA meetings and swim meets, it’s usually split about 50-50.

They will be in college soon; why can’t you trust them for one week with their childhood friends?

Vs.: No flippin’ way.

You can understand their hesi­ta­tion. This year, one 15-year-old running across the street with a pack of friends died after being hit by a car, and another teen was injured after falling from a hotel balcony.

Kids begin grinding down their parents early.

“I’ve been planning this since my freshman year!” hollered one 17-year-old from Northern Virginia, both fists in the air, triumphant after a police pat-down that didn’t get him locked up.

“We had meetings once a month since February,” said a 17-year-old Catholic school grad from Lebanon, Pa. “We met about plans, payment, what we were going to do, who was coming.” And, of course, how to get the alcohol. (It was provided by a 22-year-old boyfriend and a 21-year-old big brother.)

“I had to beg, beg my mom to go,” said a 17-year-old from Leonardtown. She and her two friends had matching henna tattoos of Chinese characters on their hips and matching short-shorts in three neon colors. I was drawn to interview them because they looked 12.

“My mom is calling me, like, every hour,” pink shorts told me.

Well, yeah.

I’d been sent to Ocean City on a reconnaissance mission, with orders to spy on your children and report back on exactly how heinously they were behaving. So I embedded myself with the partiers for a weekend.

Wow. Nothing will make you feel old like trying to keep up with 17- and 18-year-olds.

“Yeah. They have stamina," said Ocean City Mayor Rick Meehan. “We usually really hope for good weather, so the the sun tires them out.”

My experience — which ended one night with a 4 a.m. chase after two guys who were hauling a potted palm down the boardwalk (why?? I wanted to know) — was that hours in the hot sun and pounding surf mean nothing to them.