"I like beer," our youngest declares at the dinner table. Everyone laughs, and his older siblings urge him to say it again, louder. I shoot them a serious look, because their favourite thing at the moment is to get their brother to say controversial things in public. I don't want him to ruin his nursery induction morning in a couple of days, by answering the teacher's question of, "What do you like?" with a well–rehearsed: "Willies and beer."

Instead of admonishing him for saying he likes alcohol (because let's face it, until he's tried it he can't say if he does or not), I look at my son and say, "This isn't real beer."

I should have just said, "Yes, beer is lovely," and moved the conversation on because my son looks cheated and crestfallen, like he's got his references all wrong. I'm surprised that he knows what beer even looks like, but then I realise there's a line in The Tiger Who Came to Tea, where the mother in the story is very worried because a visiting tiger has eaten all of the food in the cupboard, and alas, drunk all of Daddy's beer.

If a tiger came for tea at ours and was looking for booze, he'd be disappointed. We don't have any, save the odd bottle of beer that I hide under the stairs for when R's out and I fancy an evening swig. I pop the bottle into the freezer five minutes before I want a drink. I haven't told him I do this because he'll probably laugh and say, "You think finding one beer in the house will make me want to drink again? I can go to the shop at the end of our road if I really want to get pissed." But not having alcohol in the house – as a loose rule that I set when R moved back in – feels right at present. The stuff that R is drinking now is alcohol-free and quite why I feel the need to point this out to our three-year-old son – who is confused to say the least – is questionable.

I don't think I have a problem with R drinking pseudo-beer (despite some people thinking it's a step towards relapse), but I think I'd worry if our neighbour popped by, saw the bottle and didn't spot the 0% on the label, and thought he'd fallen off the wagon, and we were carrying on as if everything were normal. It makes me question how I'd react if R did sit down one evening and pour himself a real drink. I think I'm OK with him doing exactly as he pleases now, but that's only because he's still sober.

When I've answered friends' questions about R's on/off relationship with drink, I feel like it might be more helpful to just stay quiet and let his sobriety and progress do the talking. But I can't stay silent about everything because our children ask questions all the time.

How do I talk to them about alcohol? Or rather, how do I talk to my children about the problem with alcohol? Because if there hadn't been a problem in the first place, then R wouldn't be sitting here with half a litre of impotent brown beer in front of him. He'd be drinking the real stuff.

Like all talk surrounding stuff that can sometimes be great but also be awful (sex, modern art, solitude), the joy and the pain that alcohol can elicit is hard to explain. Our older two children might realise that in our family life it has been the crux of many a problem in the past few years and we've talked about how well R is doing. But it's hard to talk about his actual problem and how alcohol became a problem in the first place.

What I really want to say is "Drinking can be fun, kids. Do it right and it can be a riot and a total pleasure, and totally fine. Do it wrong and you could end up in the gutter."

I don't want to put alcohol in the same bracket as heroin because any way you look at heroin – even if the user is lucky enough to be doing the pure stuff – they are losing. But alcohol? I have always been able to drink in moderation and R has not. One of us can handle alcohol, and the other cannot. How do you explain that to people who still have fairly idealistic views about life?

I try to answer the questions as they come, such as the tricky "sex, love and which-comes-first?" ones, or the even harder ones regarding good, necessary fibs and bad, nefarious lies. However, as hard as answering my children's questions might be at times, I realise that they are an incredibly useful way of exploring areas that I find uncomfortable or I am unsure about. And I don't always have to pretend that I know all the answers.