Tim Key: It was The Colonel's birthday. So we took him to the aquarium, obviously

It was my dear friend The Colonel's birthday, and so we all spent the afternoon in the aquarium. We'd planned it that way. When it's your birthday, you don't want to be sitting in your undies all day, killing time till evening comes, waiting until the moment the boozer opens and you can stick some stinking liquor down your throat. That's a waste. Nope, better is to rally the troops and get some stuff done.

The Colonel had been dropping hints for days that he was interested in seeing some live fish swimming in tanks. And so it was that me, Blasco, Vinehouse, DOD, Kerrie, Nishant Kumar, Alabaster and Joe scooped up The Colonel, bought him one adult's ticket and a child's cap with a cartoon shark on it, and shunted him towards the sea life.

I remember when I was a child, a large part of the joy of birthdays was seeing my parents pick an attraction and make it their business to absolutely nail organising a trip to it. When I was seven or eight years old, we'd all pile into a couple of Volvos and drive to some waterpark or other and hurl ourselves down slides. Or else my dad would root out some kind of weird outdoor centre within a 90-minute radius of our village and we'd burn down there and all put on wetsuits and try canoeing. The phrase 'those were the days' is obviously overused these days – but I would definitely haul it out and dust it off to talk about those particular days. Laser Quest! Nature trails! Ten-pin bloody bowling! THE DAYS!

And now here we all were, charging around this aquarium, like kids. The Colonel – our figurehead.

We started at the bottom, gawping at stingrays like they were going out of fashion. The aquarium had a glass tunnel, which we waddled through with these flat beasts swirling round us. It was a majestic site and we laughed at their gormless little frowns and took selfies with them gliding behind us. The Colonel clapped his little hands in delight and filled out a worksheet that was meant for children and – once we'd had enough of these queer beasts – we pressed on to the interesting stuff.

The aquarium was built on five levels – if you're interested in layouts – and each floor represented a different depth of the ocean. So the next one up was more about things like sharks and prawns, then it was things like scuba divers, and then the floor above that was more sort of otters, ducks, surfers and guillemots. To be honest, I lost interest after the sharks and mainly chased The Colonel, trying to give him the bumps and have a go with his cap. I get very jealous of people whose birthday it is and cope with it either by throwing myself into making it as special as possible for them, or else by isolating them and telling them to get over themselves.

At the top, my interest was once again piqued. It was mainly penguins and salt-water crocodiles up there and I'd seen both in films, so was predisposed to take an interest. The crocodiles seemed to like the idea of eating the penguins and the penguins seemed to know that and appeared to goad the crocs. And in the middle, with just a reinforced slab of glass separating him from both wonderful exhibits, was The Colonel, clutching his felt tip and joyfully answering multiple-choice questions. School groups bustled among him, occasionally asking their teachers how he fitted in.

We got chucked out, eventually, and collected a photo of us that the aquarium had taken in the shark bit, and then we reconvened in a pub 10 minutes away and discussed our findings. It was a great activity, we agreed. And then, gradually, the booze began to flow. And it submerged our favourable memories of the aquarium, and we chanted at The Colonel, and he touched the peak of his cap, and he chuckled away.

Tim Key will be performing his show Single White Slut at the Duchess Theatre, London, 28 April-2 May, 7.30pm.