“You must see some sights,” people say when I tell them I’m a campus security guard. I reckon it’s code for, “How often do you catch students bonking in a hedge?” (The answer’s not often – no-one likes getting their stroke interrupted by a squirrel). Apart from stepping over the leavers who christen parking bays on the night of the summer ball, undergraduate sex antics is something we can thankfully avoid. That is until Shag Week rolls around.

Shag (Sexual Health And Guidance) Week runs at different times around the country. It showcases everything students could ever want to know about sex, warts and all.

We always tell the freshers to go, even if they lost their V-plates back with their GCSE results. Firstly, Shag Week teaches them there’s nothing shameful about a rash. Secondly, it sheds light on consent, STIs, and all those other things that parents, teachers and university staff are often too embarrassed to talk about.

Some kids begin their three years at university wrapped in cotton wool. I’ll always remember a group of students who on the surface had the dream setup: an off-campus, city-centre flat opposite a pool club with unprotected Wi-Fi.

But something about the club’s façade seemed off. There was only one table. There was an England flag in place of a business name. And, according to the only one of the students who ever opened the curtains, there were nude silhouettes in the club’s upstairs window.

One afternoon, one of the students came home to find police vans parked outside the club’s fire escape. The students had been living opposite a brothel. They were shocked. Did stuff like that really go on close to campus?

Shag Week’s about reminding people it does. We guards know when Shag events are underway because we’ll discover nursing students playing capture the cock ring. We’ll patrol past the canteen comments desk and see a bowl of Durex condoms at one end, and a cardboard bin full of chlamydia self-testing kits at the other.

The mood’s light, even for security. If we’re not chasing the bloke who deals Viagra in the student union, we’re asking the president of the photography society why there’s a double mattress in his darkroom. Or we’re offering a shoulder to the girl whose squaddy boyfriend gave her crabs (which he swore he caught through sharing towels).

Not all staff appreciate the Shag Week hi-jinks – some even ask the vice-chancellor to take down posters. This is usually a sign they’ve either got short memories or aren’t getting any themselves. Fair enough, no-one wants to teach a class where the kids at the back are playing pin the junk on the hunk. But academics would do well to remember teenage passions run high, especially when they’re unaddressed.

And the Shag Week reps are smart. As well as discussing sexual positions, they’ll advise on when free clinics are open, try to get photos with the senior management team, book speakers from the International Union of Sex Workers, and share anonymised sexual assault stories with the new intake, warning them how ugly a dalliance can become. We’ve seen this first hand when a girl came to us white with fear, saying the bloke she’d brought back home had done something.

An hour earlier the pair had been at the student bar arm in arm, giggling. None of us would’ve suspected anything.

If anyone comes to security guards for dating advice, we’ll be as frank as our job contracts allow. My own tip: never lust after anyone who’s too charming. You want to wake up to someone real, someone you can stand to eat your Ricicles with.

However, security staff aren’t professionally trained in these matters. This is why we’d encourage welfare staff to get involved in Shag Week – and maybe even do a couple of night shifts with us to see what really goes on after hours.

Join the higher education network for more comment, analysis and job opportunities, direct to your inbox. Follow us on Twitter @gdnhighered. And if you have an idea for a story, please read our guidelines and email your pitch to us at highereducationnetwork@theguardian.com.

Looking for a higher education job? Or perhaps you need to recruit university staff? Take a look at Guardian Jobs, the higher education specialist