Parents! Are you worried about your teenagers? Do you feel the world is just too sexy these days? Do you suspect your teenage child’s hormones are out of control? Have you feared there’s nothing you can do to fight the horny and inevitable tide of biology?

Well, rest easy, parents. There’s a simple way to kill the mood: just send your kid to a St Mary’s school dance.

On Saturday night, after our first week of classes, Mary Kate and I strolled into the cafeteria. I turned to her and walked backwards like a school tour guide.

‘Welcome, you sexy young thing! To your left, you will see the giant, bloody crucifix that gives our venue its special Spanish-Inquisition ambience. To the right, observe the line of cranky nuns and priests. Notice their lips pursed in disapproval, their eagle eyes fixed on the dance floor. Fun fact: under those habits, they’re armed with Super Soakers of Holy Water to extinguish the satanic fire that will erupt should your bare knee brush an inch of generic boy khaki on the dance floor. And, finally, inhale the irresistible aroma of stale French fries, lest you should forget for a moment that we are, in fact, in the school cafeteria. As Marvin Gaye would say, Let’s get it on!’

It was 7.30 p.m. The dance had begun half an hour ago, and it was still painfully awkward. Even though speakers were blaring a Katy Perry song with every other word bleeped out (fuckin’ St Mary’s censorship – what do you even bleep out in a Katy Perry song? ‘Cupcake boobs’?), no one was on the dance floor, and the sexes were completely separated. The girls were clustered in little groups, swapping lipgloss. The guys – ninety-nine percent of whom were dressed in blue button-down shirts and khaki shorts – had staked out the snack table, where they were throwing tortilla chips at each other and shaking up cans of soda.

‘It doesn’t look like anyone’s really mingling,’ Mary Kate said.

She had unbraided her hair so that it rippled down her back like a Disney mermaid’s, and was wearing a short dress she probably thought was sexy. In reality, she’s so cute and tiny that she looked like a fourth-grader on school picture day.

I, on the other hand, am so curvy that everything looks slutty on me: I could wear Sister Hellda’s nun’s habit and all I would look like is a sister of the Kardashian order. So I was rocking kind of a rebel look with jeans, a vegan leather tank top, and my hair moussed and gelled into what MK calls my ‘lady fauxhawk’.

‘Oh my gosh!’ Mary Kate said. ‘Look who it is! Theology John!’

‘Who?’

‘That cute guy from my theology class! Remember?’

‘Ohhh. That guy who you cried about because he heard your stomach growl during a pop quiz?’