too many kids can spoil a peaceful evening

So tonight the kids had friends round after school...twins for the big one and a friend for the little one. Five kids in total.
It was all going extremely well. They were playing so well together I even found myself with time on my hands. Ooooh, I thought, I'll do this again...
Then they went to play out....and were joined by a million kids from the neighbourhood. Nine kids playing nicely in our garden.
How lovely.
Couldn't last could it?
It soon went pear shaped. They started fighting in lumps. Tears and tantrums all round. With me as the referee.
I was glad to see the back of them. 
I'll stick to two kids in future thanks.