For not letting my 9 year old daughter spend the night at a friends house ?
@princecharming: Tonight or ever? Never onna school night.
My criteria was always whether we knew the family (neighbor, church, family friend). If any of these are the case, then maybe consider letting her. If it's just some kid at school and you don't already know the parents, then no, trust your instincts.
Keep in mind, that this is the age when sleepovers are big and it will only get worse/more frequent.
We never allowed it when we didn't know the parents. 4951