I took my daughter for a bike ride this evening on the cycle path near our house. While on the ride I spotted my 11 year old son's bike and helmet abandoned just off the path - he was out with his mates and had obviously left it and was playing down by the river. 20 minutes later we came back and the bike was still there - I could hear them all in the distance, but was slightly annoyed that he'd left it well out of sight on a fairly busy path. So I picked it up and took it home. I thought that coming back to discover it missing might teach him a simple lesson in bicycle security. Anyway - his mother was not amused when I got home. She thought it was a bit harsh, and was worried about how he would feel when he discovered it missing. However, given that he is pestering us to buy him a new £450 mountain bike (and we're just about to do just that) I felt that learning this lesson might save him a more painful lesson in the future. After 20 minutes of explaining my reasoning, I got fed up with the look of thunder on her face, So went to find him. I found him where he'd left his bike, with his mates, obviously trying to work out what to do. He told me his bike had been stolen, and said he'd left it hidden in the bushes (a story which all of his mates backed up.. What are friends for!) - I didn't make him suffer, and told him his bike was safely locked up in the garage at home, and explained the reason for doing it. He was a bit annoyed, but mostly relieved, and totally understood my actions. Happy days, right? No - now I'm getting the silent treatment from the other end of the sofa from the girlfriend. Am I in the wrong here? What would you have done?