You are second in line in a long queue in a supermarket. You have been waiting 20 minutes to check out already. Almost everyone in the queue has full trolleys and the 12 items or fewer tills are very busy too.
As you wait patiently you are surprised to see a young man with a basket of groceries jump right to the head of the queue.
'Sorry,' he says, 'I need to get out of here to see my Mum in hospital. I will miss visiting time if I queue.'
The person in front of you does nothing.
What should you do?