When he went back to school after the summer holidays, I'd already decided to let him come home on his bike on his own, and I'm happy to let him go across to the local park to hang out with his mates at weekends.
He's sensible and conscientious and always returns home at the agreed time, though I was a bit disturbed when I asked him how he knew what the time was and he replied: "I ask a stranger."
So we bought him a cheap watch for his birthday and agreed a few rules to keep him safe, such as:
• Make sure he looks drivers in the eyes at zebra crossings to make sure they're not changing a CD or putting on their mascara;
• Memorise mine and his mum's phone numbers until they come as naturally to him as his name;
• Avoid saying 'Boo' to geese. They don't like it.
All well and good. But give a boy some rope and he will inevitably want some more, so I wasn't surprised when he asked for more responsibility, namely: could he bring his younger, seven-year-old, brother home from school, too?
Now this was very tempting. I'm not very good at school run small-talk: all that, 'How was your holiday?' bonhomie from people you don't really know and who certainly aren't interested in the answer. It's like a daily visit to the hairdresser.
But as much as I trust my eldest boy, the youngest is as daft as a brush and I think the responsibility of trusting the eldest to keep the youngest safe as well as himself would be just too much – and probably illegal.
Is it? I wasn't sure, so I turned to Mr Google and found this: "There is no minimum age at which children in the UK can be left on their own, nor do laws specify how old someone needs to be to babysit.
"However, if the babysitter is under 16, then the parent remains legally responsible for the child's safety.
"Under the Children and Young Persons Act parents in England and Wales can be prosecuted for wilful neglect if they leave a child unsupervised 'in a manner likely to cause unnecessary suffering or injury to health'.
"Punishment ranges from a fine to 10 years' imprisonment."
Without legally specified ages to guide us parents, this seems confusing, but children's charity, the NSPCC, advises common sense, advising that children under 13 should not be left at home alone for long periods and that children under 16 should not be put in charge of younger children.
The charity says: "For example, most parents would think it's OK to leave a 16-year-old alone for the evening. But to leave them for a week would be unacceptable.
"Many young children play outdoors with other children without supervision, most people would agree that this is an important part of growing up.
"To leave children outdoors for a considerable length of time though, or to allow them to wander off without knowing where they are going, would be unacceptable.
"You are the best judge of your child's level of maturity and responsibility."
OK, that doesn't totally address my issue at hand because it says nothing about siblings walking home siblings from school, but it does make me look at my 10-year-old son with more of a microscopic eye and ask myself: is he mature enough, is he responsible enough to look after his little brother when I'm not there?
Again, I imagine, it's a case of using common sense. Putting an older child in charge of a younger in a kitchen filled with knives is probably not the greatest idea.
But how about walking 500 yards home from school? Is that a common sense thing to do?
Other parents might doubt the sense of ANY situation being suitable for a 10-year-old to be in command of a seven-year-old, no matter how level-headed the big sibling.
But how about leaving them to play in the park for an hour after you've taken them there and back?
I don't hold with the notion that there's a paedophile behind every bush.
In fact, I believe that children are invisible to most adults, until they get into difficulties, and then an adult would come to their aid. But perhaps I'm being naïve.
Other parents' opinions on the issue are pretty much of the 'it depends' persuasion.
Many believe that allowing a child to walk home from school on their own depends on the child's maturity and nature, and how busy the roads are on their journey - and they believe the same applies to allowing a child to accompany a younger sibling.
One mum said: "It doesn't matter how sensible the older child is, if the younger sibling is a bit scatty or wayward, then it's unfair to burden the big brother or sister with the responsibility of keeping that child safe. They have enough to worry about keeping themselves safe."
"Step one for a week or two I walked 3/4 of the way with him then came step two, I only walked half way for another week or so.
"Then step 3 I would walk to the end of our street and see him off there.
"And we did the same thing when he came to walking home by himself. This all started in year 5."
It seemed like a sensible approach for my own dilemma, too. I was determined to let my oldest son know that I trusted him - and also to make it clear to his younger brother that he had to abide by his brother's instructions.
So this is what I did: sitting my 10-year-old down for a father-to-son, man-to-man tete-a-tete, I told him that I agreed with him, that he should be trusted more and that he would be doing me a huge favour if he could look after his little brother every now and then in the not-too-distant future while I did hugely important stuff like iron sheets.
He was chuffed to pieces, before asking: "When?"
"Er, soon," I replied.
I didn't mean it, of course. I just wanted him to FEEL empowered.
But then he piped up: "How about this week?"
And I said, against my paternal instincts: "Sure thing. Why not?"
So on Friday, on the occasion of my oldest son's birthday, I sent him off to school with my youngest and waved them goodbye.
"See you tonight," I said.
And then I watched from the window as the oldest took his brother's hand, stood at the kerbside, looked left, looked right, looked left, looked right again, looked left again, and then right again, and then another left, until he was a thousand per cent sure there was no traffic coming before he hauled his brother across the road.
And the second they were out of sight, I legged it out the door and then spied on them at a safe distance until they walked through their school gates, and then, six hours later, hovered out of sight as big bro walked little bro, hand-in-hand, all the way home.
Safe, sound and none the wiser that their dad isn't quite ready to cut the housedad's apron strings just yet!
More on Parentdish: