He didn't tell her he was leaving her there and understandably she got upset when she couldn't find him and didn't know when he was coming back. I don't mind her being left at parties as long as it's explained that we're coming back at a certain time etc.. She's generally happy staying places and has settled into school brilliantly. However, I always take care to explain if I'm leaving her somewhere, where I'm going and when i'll be back. He's dropping her back this afternoon and I wondered whether is should have a little chat to explain this? It's reassurance for her.