Moved house a few weeks ago and this morning saw the girl next door. Asked her to come over after school with her kids. They never turned up, I thought they might have been held up at school. After about 45mins I went up stairs. and saw her kids in the garden so I popped round and knocked but no answer. I know I'm being a bit socially retarded here but what do I say next time I see her? Do I knock and say something like "I think we got our wires crossed, I was expecting you, maybe we can arrange another time". Or do I just wait till we bump into each other again and mention it?