Planning Ds's 3rd birthday and wondering who to invite, he goes to nursery a couple of days a week and has some friends he always plays with, so obviously will invite them, is it expected to invite the whole class from the days he attends ? also if he has been invited to a party of an older child (parent a friend of mine so the child isn't a 'friend' as such) should we invite them too ? Cost does some into it otherwise we would just invite them all !