Goedele Liekens from Belgium said British parents shouldn't be so "prude" when it comes to talking to kids about having sex.
She told Radio Times: "Parents should broach the subject of sex as soon as their children can talk.
"I have two teenage daughters and when they were younger we’d watch Bob the Builder and I’d say: 'How do you think Bob feels about Wendy? What would they do if they were in love?’"
Liekens continued that parents don't have to particularly go over the details when it comes to discussing sex, but be open with their children about what couples do when they're in a relationship.
But Justine Roberts, Mumsnet CEO isn't quite sure that kicking off the birds and the bees talk with Bob and Wendy is the best way to start.
She told HuffPost UK Parents: "Not every parent is going to want to 'go there' where Bob and Wendy are concerned (we're not sure we even want to go there ourselves).
"But on the whole, Mumsnet users agree that - with sex education as with most other things - keeping the lines of communication open with your kids is always the way to go.
"Good information leads to healthier and happier adult relationships, so a little bit of parental embarrassment is probably a price worth paying."
The UN ambassador, 52, is a qualified psychologist and television presenter who visits schools around the world as part of her work with the United Nations Population Fund.
She said in Belgium parents are much more liberal in their approach to sex.
But does that mean parents should be more liberal? Annie O’Leary, Editor in Chief of Netmums, said while conversations should be open, the choice on what you discuss with your children should be exactly that - a choice.
She told HuffPost UK Parents: "How the subject of sex education is tackled at home is up to individual families, though most Netmums would agree that the top priorities in any discussion on the subject should be making it age appropriate, and in such a way that it invites children to feel free to ask any questions they may have.
"Equally, while it’s certainly a novel idea to introduce Bob and Wendy’s sex life to children at such a young age, the basic principle of talking about healthy relationships with children, and giving them easily identifiable examples of what healthy relationships look like, has been welcomed."
What are your thoughts - should Bob The Builder spark a conversation about sex?