Suicide bidding is when someone in an auction bids more than they can afford or think the item is worth. Think of it like when you go to the store with your parents and you see a toy you really want, but it costs more money than you have. If you begged your parents to buy it for you even though they couldn't afford it, that would be like a suicide bid. It might seem like a good idea in the moment, but it can get you into trouble and cause problems later on. So, it's important to only bid on things you can afford and really want!