Three weeks ago, my son Benjamin, aged 3 and a half bought his first goldfish. This was a big event, meticulously planned. Grandma and Granddad took him to the garden centre where they choose two fish (his had a black fin and tail; his sister's was a more ordinary looking specimen), a tank, gravel, weed, food and a fluorescent plastic lighthouse for the fish to swim around.

All the way home from Grandma and Granddad's he gave me strict instructions to "hold on tight to the tank" to make sure that the fish didn't fall out as the water sloshed around on my lap whenever the car went round a corner.

We put the tank in the bathroom (the safest place away from the cat) and Benjamin watched the fish nibble the gavel and dart about as he sat in the bath or on the toilet!

Then the fateful day came. Benjamin was at nursery school when I noticed the two goldfish bodies floating about in the water. Mild panic took over and I even phoned my husband at work to break the bad news!

"What shall we tell him?" we asked ourselves. "Shall we buy two more and hope he doesn't notice or should we tell him the truth?" It was 3 o'clock on a Friday afternoon and a dash to the nearest goldfish supplier to try and match up both fish (especially one with a black fin and tail) was not an option I relished. There was nothing for it but to pluck up courage and tell him the truth.

As I strapped him into his car seat on the way home from nursery, I took a deep breath and said "I think something has happened to your goldfish Benjamin ..., I think they've died".

"Died? What does that mean mummy?" he asked.

"Well, I think the water was too cold for them and they're not alive anymore. They're dead."

"Dead?"

"Yes. We'll go and have a look at them and see what you think."

We let ourselves in through the front door and Benjamin, in a flurry of excitement and anticipation, rushed upstairs to see what had happened.

"They're not swimming any more. Are they asleep?" he said.

"No... they're dead... not alive anymore. That's just what happens, especially if they get too cold. They couldn't breath."

"Oh. Can I touch them?"

"Yes, if you want to."

I scooped up a little orange corpse and laid it gently on the end of the bath. Benjamin stroked the fish tenderly and asked how it breathed usually. Tempted to give him a biology lesson on the fish respiratory system I stopped myself, pointed to its gills and left it at that. He seemed satisfied with the answer and turned to me with glee. "What do we do now?"

"We could bury them in the garden." His eyes lit up.

"Yes... then can I watch Playdays?"

What's the point of the story I hear you ask. Well, its the realisation that our son is growing up and that telling him the truth can be scary.

As parents of DI children, my husband and I had intended to be open with our children about their conception, but for adults, telling the truth about DI holds so many feelings. How will they react? Will I feel rejected? Will they be confused, want to know more or need answers I cannot give?

This episode, although apparently trivial, taught some valuable lessons. That the truth is easier than a lie, that children can process information more readily than we think and that we must acknowledge their desire to grow, learn and trust.

Although we have the "My Story" book and think that we know how to tell, we cannot manipulate the time or circumstances but will probably sense when the moment is right and will respond to a cue from the children.

We hope we will be honest and close enough to our children to sense when a simple question leads to a simple answer and take it from their.

The memory of those cherished goldfish lives on!