DS has been invited to a party from a child he goes to nursery with. The thing is we don't know the child, never met them let alone the parents. DS is only 2.5 so it's a parents stay party. So I'm after some advice really as to whether we decline but when I've asked nursery staff they said they do play together. I wouldn't invite a child I don't know to DS's party. Also I know other children from his group have not been invited so it wasn't an 'invite all from the class' thing.