“Does your child ever use violence?” The assessment form asks.

“No.” You tick confidently.

If we put our son on the naughty step, he’d climb to the top of the stairs, fall down the stairs, climb back up the stairs again, fall down again, this time pulling all the junk on the landing down with him. We’d find him under an avalanche of boxes, either laughing hysterically, or unconscious. Either way, no lessons would have been learnt.

What we do have is a naughty bag. To be specific, a rather nice naughty bean bag with space rocket design.

I doubt baby-sister-tipping will ever become part of the Olympics. She sits unaware, fat and happy, tasting the world one object at a time. He makes it look like he’s going in for a hug, but before you can get there she’s down, her head making a soft “pock” sound on the rug, and he’s scrabbling to get full points by sitting on her.

You’re on the phone with Grandma so she rides along for the arrest. You take him to the bean bag. You explain to him why he’s there and what happens next, but he rolls his eyes. He knows his rights.

You tell your mum that at his age the maximum is three minutes on the naughty bag. She tells you some funny parenting stories. Then you have a general tidy round and change your clothes. You watch your daughter playing nicely on her own. You go cold.

The last two and a bit years flash before your eyes. Turns out that’s all you can remember of your life. Your son has been on the naughty bag for nearly an hour.

“Hello son.”

“Hello Daddy.” He replies happily, still sitting. He’s playing space rockets.

“Would you like to say sorry to your sister for pushing her over and sitting on her?”

“OK!” He jumps up and happily runs to perform the ritual apology.

“I think we need a more boring naughty bag.” You tell Mummy later.

She nods.