A teenager got away with painting a 60ft phallus on the roof of his parents' home for a year before his parents found out.
Rory McInnes, 18, climbed on to the flat roof of his parents' home and daubed the symbol using a tin of white paint, after watching a programme about Google Earth.
Web surfers can view detailed images from satellites using the Google software, enabling them to zoom in on their homes to see them from above.
But parents Andy and Clare did not discover their son's rude artwork until a helicopter spotted it on top of their home near Hungerford, Berks.
The pilot called The Sun newspaper, which then contacted Mr McInnes to tell him.
Mr McInnes, 54, a company director, thought the newspaper was having a joke.
He said: "It's an April Fool's joke, right? There's no way there's a 60ft phallus on top of my house."
However, when he asked each of his four children if there was indeed the image of a phallus on their newly-completed roof, Rory owned up.
When Mr McInnes phoned his son, who is currently in Brazil on a gap year, the teenager said: "Oh, you've found it then!"
The boy's father appeared to take the prank in good humour.
But he said: "When Rory gets home he will be given a scrubbing brush and white spirit and he can go and scrub it off."