so, I was at the supermarket today, just getting a couple of items. I was standing in the queue behind a customer and had my items on the belt. A little girl - about 6 or 7, pops up between me and the guy in front and anounces "I'm next". I smiled and said "do you not know you have to queue". "no I don't, I'm next" she replies. I shoved my stuff to the end of the belt so there was no room for her to put her stuff down, at which point she starts grabbing at them to make space. At this point I got a bit cross, told her not to touch my stuff along with a stern glare. She backed off and started mumbling about telling on me. So AIBU - should I just have said she's just a little girl - let it go or do you think I was right to correct her bad manners?