another prick...

I am standing in the queue. I take a step forward to see if another cash desk is open - it isn't so I take a step back, but... suddenly there is a guy standing next to me, he puts his stuff on the desk, when I tell him: "Excuse me, but I think I was in front of you", and he goes: "I thought you were leaving", I reply: "Well, I've got things I haven't paid for, so I can't leave, can I?". His answer: "I don't care". Now, what would you answer to that? "Here comes another prick?" I'm pretty sure he knows that and... he doesn't care...