The other day my daughter Livi, who is six, came home from school saying she had been told off for kissing her "boyfriend" in the playground.
"And she was kissing some other boys! On the lips as well!" chipped in her brother, Toby, 8.
They soon got distracted and started talking about who had won the most marbles that lunchtime but it got me thinking – when is the right time to talk to them about the birds and the bees?
When does Livi's playground canoodling go from being cute and innocent to being downright inappropriate?
Should I take her aside for a serious mother-daughter chat or is she, as I think she is, still too young to need to know the mechanics of sex and relationships?
I asked around some parents with children of similar ages and it seems that the norm is that most children know sex exists, but don't really know much more than that.
One friend, Charlotte said: "I got caught out on a long car journey when Archie, who was then about seven, suddenly asked apropos of nothing at all: 'How long does Daddy have to leave his willy in your bajina?' The question came totally out of the blue – and I really did blush – and mumbled something vague, trying to keep the balance between honesty without being too graphic and sensing that my husband sitting next to me would like me to say hours! I braced myself for the next question but that was it.
"I don't think they can deal with too much information at once and I think drip-feeding it is good. My children are now ten and eight and most the questions they ask are after they have had sex education at school and are along the lines of "Is this really true? Gross."
Another friend, Fiona, was recently discussing sleeping arrangements for a sleepover. "My eight- year-old son was asked if he'd be happy to share a blow up bed with my friend's nine-year-old daughter. He said: "That's fine – I don't want to have sex or anything." We were in fits – where on earth do they get this stuff from?"
Other friends have taken the option to talk about sex in the context of animals – Siobhan said: "When a wildlife programme came on showing animals mating, I seized the opportunity to explain. My children are eight and nine. They get the "willy" bit but they still think a baby comes out of a mummy's tummy – I haven't explained where it comes out yet! They also think you have to be in love to have babies, which is quite sweet."
Katrina had a chat with her daughters about sex and bought a book Just For Girls for them to dip in and out of when they felt they wanted more information after they had had a sex education lesson at school.
Sarah took a similar approach: "My son was in year six when they watched a DVD about "growing up." After he'd watched it in school, we watched a similar one on the web and talked about any questions he had. I figured it was easier to say, 'If you've got any questions, just ask me when you're ready', rather than make a big thing of it."
Child psychologist Laverne Antrobus agrees that there is no need to bombard very young children with too much information. She said: "I think "special cuddle" can cover it for quite a long time! There really is no need for children to know graphic details when they are very young."
"I think the most important thing is that children see sex in the context of a loving relationship. This is where parents really have to do their job – the biology will be covered at school but the relationship side will often be mainly down to the parents.
"The best thing to do is take the lead from your children. When they ask questions, you will get a sense of how much information they are ready for. Books can work well to back up what you have told them – I like Usbourne Pocket Science's Where do Babies Come From?
"Try to keep in touch with what the school is teaching and when so you can be ready to answer any questions they have.
"That said, especially when they are older, you will need to expect some embarrassment on both sides. I currently emphasise the importance of taking responsibility in relationships to my teenage children – they don't like hearing about condoms from me but I'm their mum and that's my job!"