Katy Perry after accepting the "Favorite Pop Artist" award at the 2013 People's Choice Awards in Los Angeles.

London - We’re in the car on the M1 heading towards a ‘fun’ pool for Gracie-in-the-middle’s belated birthday treat. Me, my nine-year-old and six of her school friends. They are singing along to Katy Perry on the radio at the top of their voices.

‘Last Friday night, we went streaking in the park, skinny dipping in the dark, then we had a menage a trois. Last Friday night. Yeah, I think we broke the law, always say we’re gonna stop, Whoa-oh-oah.’

I am not singing along for a variety of reasons. First, I fear I may be lost. My subconscious is desperately doing everything it can to avoid going to a huge water park at nine o’clock on a Saturday morning. It’s not sure my immune system can cope. Second, my singing is legendarily bad. Pudsey the dog would beat me in a karaoke contest.

But the main reason I am not joining in is that I’m uncomfortable with such grown-up lyrics blasting out of the mouths of under-tens. It makes me squirm in my seat as their little voices talk of drinking shots, getting arrested and maxing out their credit cards.

I’m not prudish (I used to edit Cosmo, remember) but I know for sure that I don’t want to be one of the gang. It’s suddenly obvious to me that I won’t be one of those moms who tells the world ‘she’s my best friend as well as my daughter’.

As my eldest two girls grow up I am now peeking over the precipice that is the teenage years. And crikey it looks scary.

I can see the temptation to be their best friend so you can monitor all that forbidden activity at close quarters, but it feels instinctively wrong. Apart from the 33-year age gap, friendship with your little girl is surely doomed for so many reasons.

When we get to the pool, the girls undress chaotically, leaving their clothes all over the floor in a tangled mess, underwear strewn everywhere (not unlike the character in Katy Perry’s song).

Two other moms have come to help at the water park, but I am the only one going into the busy pool.

It takes all my willpower not to tie the over-excited nine-year-olds together with my knicker elastic. I try my hardest to keep an eye on all of them all the time for almost an hour, chasing them from ride to ride like a demented sheepdog.

It’s terrifying. Even more terrifying than the Space Bowl slide for which I accidentally queued up and which gave me such a bad wedgie I feared it may have to be surgically removed. Now I know what Mary Berry really means when she talks of a soggy bottom.

I was overwhelmed with relief when it became clear that it was time to go home. Who’d have thought the words, ‘We’ve had to shut this ride because a small child went to the toilet in it’ would have produced such joy in an adult?

As we headed back to the changing room, groups of older girls had arrived at the pool, minus a parent to watch them. They seemed more interested in the teenage lifeguards than the rides. That’s my future stood there in glittery swimsuits, though, isn’t it?

The teenagers were busily brushing their hair to make themselves look perfect while my little menaces were refusing to brush their hair or even consider putting their coats on. They appeared to be wearing each other’s clothes, too.

Afterwards, we all went for a birthday pizza. I was thankful to see that my would-be teenagers were still young enough to choose the children’s menu. But when Gracie asked to try a Diet Coke it put me on the spot.

It was clear that some of her friends were allowed to drink it and I didn’t want to embarrass her by refusing her the chance to be more grown up. But Diet Coke? At nine?

I said yes, breaking one of those vows I made before I had children about banning all caffeine-filled fizzy drinks.

She didn’t really want the drink, she just wanted to be allowed to have it. And I think I was right to say yes, but who can say.

In the same way that Katy Perry is only one step away from Rihanna, Diet Coke is on the path to alcopops. But you can’t protect them from everything, can you? - Daily Mail