Genuine AIBU here. My twin girls (3 and a bit) just started kindergarten, it's in Germany, the kids go there until they start school at 6. One of the older girls has taken a bit of a shine to my kids and yesterday her mum said to me that she'd like to come visit and play with them. We started discussing times and suddenly they're coming that afternoon. When they arrived, the mum was like "can I leave her with you? I have to go and get my older daughter" and I said, oh OK sure, pick her up in an hour? And she frowned and was like, oh that's not a lot of time, what about two hours? I agreed because my German's shit so I'm not great at arguing. Kid was nice enough, and my girls are still quite little so it's unknown territory for me but surely you don't drop your 5 year old off for two hours with a mum you've spoken to about 3 times and who doesn't even speak your kid's language particularly well?