I've seen on Mumsnet that at school age children's parties there are often parents turning up with uninvited siblings because of childcare issues. My DS is 20 months, so I'm not there yet, but if a child can spend all day at school, why would parents need to stay because of childcare issues? Surely it's up to the organising parents to ensure they feel comfortable with the adult:child ratio (asking their friends to help out if necessary)?
I don't recall my brother ever coming to a party I was invited to, with my mother, a single parent, unless the hosts were good family friends and wanted my mother there to help out and/or my brother there as he was friends with the birthday girl's little brother (and this was usually reciprocated when one of us had a birthday).
Is it unreasonable these days to drop off and pick up, or will I be expected to hang around, with DH looking after the other child (or vice versa)?
I'm not talking about SN children.