We both packed both lunch boxes on the first day back

I got up early to pack the children's lunches as a small surprise for the first day. My partner had got up earlier, also as a surprise, and had already packed both boxes and put them in the bags. I packed two more and put them in the bags without looking. The younger one came home and announced that he had eaten 'both my lunches' and called it his favourite day of school so far. His sister brought her second box back untouched and told us, quite fairly, that we need to talk to each other.