My two spend a lot of time with these children, playing out and in each other's houses, but there are times when they have schoolfriends over for tea/sleepovers and they don't always want them involved. It gets very awkward!
Trouble is the other two are naturally more dominant than ours (and their friends) Twice recently my youngest (aged 7) has had a schoolfriend round and because they were playing out and my neighbour's son joined them, he expected to come in with them when they did. Then he'd start, organising a team game so he and ds's friend were playing against my ds which ended in tears, persuading ds's friend to run off and hide, again leaving ds out, and he completely trashed ds's room, cupboards emptied, everything upside down
On each of these occasions my ds had a different friend but my neighbour's son acted the same, (I don't know what our foreign students thought who were staying with us!) so both times I took him back to his mum. Her reaction was "Oh bless him, look how left out he looks"
His older sister is a bit like this too with my eldest if she has a friend round. They each had a friend this morning and stayed for lunch, but when the other two knocked I just told them they had friends round and wouldn't be free until late afternoon. It didn't stop them knocking though, and after myself, dh and dd had told them on three separate occasions we just ignored the door. Then the notes started coming through the letterbox, the first from my neighbour's dd aged 10 saying her and her brother were putting on a show for "all the children in our house to watch!" and gave a time.
Soon afterwards another note appeared from her brother saying "PLEEEEASE COME AT 11 o'clock!" I went round there and politely said the children and their friends wouldn't be free as they just wanted some time on their own but our two would knock when their friends had gone. Half hour later the older one knocks for my dd, tearful, in a state and saying all her practising had been wasted! My dd's friend who is older than our children, (13!) hadn't been keen on going round there as she doesn't know them, and I didn't want to force her. My dh stepped in at this point and said "Look we're not free until much later, you were told earlier so you can't blame us for your time being wasted". She didn't like this at all and then came back with her mum
who asked what was going on. She was v apologetic, her dd had been pestering to invite our two to watch this play not telling her they had friends round. She then marched her home and it's been all quiet since
I need to sort all this otherwise summer hols will be a nightmare won't they! These children don't seem to have others round that much, I think they just rely on ours