My little sister and I were naughty. We went to the tattoo parlour without telling Mum.

Out of almost nowhere, Laura decided to get inked. I’ve already got two tattoos because I am Well Hard, so naturally I high-fived her and told her to get one of Satan riding a Harley Davidson on her chin. Not really. I told her to seriously consider the permanence of her decision. Not really. I said I’d go with her to make sure she didn’t get shafted by a pirate with a biro and buy her a pint afterwards.

Three weeks later I watched a woman stick a buzzing needle into my sister’s ivory skin. For the smallest of moments I almost flew over and punched the bird through ten walls, but then I remembered that my sister had chosen to be there, and that since she pushed out two big babies without pain relief in less time than it takes me to choose a new shower gel, my protectiveness has been a little surplus to requirements.

Tattoo parlours can feel like the scariest places in the world at first.

The chair looks like it’s been customised for extra pain by a Nazi dentist. The steriliser seeps into your imagination and makes you envisage you’re about to have a major organ chosen for sacrifice by the rolling of a pagan twelve-sided die. The music sounds a bit eerie, like that scene in Silence of The Lambs where the guy sticks his winkie between his thighs to make a noonoo. And there are always at least two men with varying degrees of grumpiness sitting around with their ear lobes blown open like cartoon cigars lit by dynamite. (I always want to stick my finger in those strange cultivated orifices. But they wouldn’t like it. I know this because I once licked a woman on the tube and have been scorchingly aware of what’s socially acceptable ever since.)

Then you realise that, actually, they’re just ‘places’. Like the hairdressers, or Matalan. There’s an element of risk, yes, that you will come out with the inky equivalent of a blue rinse or velour jogging bottoms; a mistake that will leave you hacking tears into the mirror once you get home, but mostly it’s just someone doing a job for you. Just – know what you want, and make sure you ruddy come out with it.

Having said that, even if you’ve spent the whole time relaxed and chatting about the tattooist’s nan Eileen and her flatulent budgerigar Albert, you can’t help but feel a little dangerous once you come out. Like if the Russian mafia swept passed and asked you to hold a mysterious package for a bit you might just say yes for the heck of it. YOU HAVE A TATTOO – YOU ARE DOUBLE-HARD AND THE LAW CAN LICK YOUR TOILET.

Laura emerged with a beautiful butterfly on her back and I bought her a Magners down the road. I had a congratulatory pint of John Smiths on behalf of Dad even though I knew he’d spin under his rose bush if he knew either of us had opted to have our skin marked like common sailor’s tarts. We wondered how we’d tell Mum. Laura, in the spirit of the moment, merely posted a picture on Facebook saying “Mum, I’ve got something to tell you…” And we giggled like rebels, like Russian assassins, like sisters under a duvet, like adults who should know better but don’t want to just yet.

You can hear Sadie doing stupid voices on CBBC’s Walk On The Wild Side all this week and next, 4.30pm. If you want.