Oh, you're not joking

Today I went to Wal-Mart.  Shut up, it's not something I do often, but I needed pectin and flour and I knew they had the former.  Once I had grabbed the few things I needed (carrying more than my recommended weight limit, by the way, stupid recuperation) I went to one of the self check-outs and put my stuff on the belt right away, so as not to strain myself (again, recuperation, pity me).  The woman in front of me was just finishing up, bagging her 5 packages of bacon (no, really) when the belt with my items rolled up toward the scanner.  Instead of paying and leaving, she attempts to find a divider to put in front of my groceries.  Unfortunately there were none there, in the self check-out line.

Her:  Oh, sorry, there are no dividers, I don't want your stuff to get all mixed up with mine.
Me:   Really?  You forgot what you bought and you don't want to ring up all of my stuff as yours?
Her:  Dirty look.  Pays.  Stomps away.

Okay, yeah, I was snarky, but in my defense, I thought she was kidding, she was kind of smiling at me when she started talking to me!  Really, wouldn't you think she was kidding, too?