I don't I posted this, yet, but if I did, I apologize.
Way back when I was working on my undergrad degree, I worked in a fast food restaurant part-time. There was another cashier and an assistant manager who were friends outside work, with whom I'd gotten along nicely, or so I thought. Both were in their late 20's- in other words, old enough to know better.
One day, during the lunch rush, when we were packed to the gills, the assistant manager in question was assigned to work drive-thru. The cashier and I were on the front line. But then the drive-thru alarm kept going off. And going off. And going off. Then people came in to complain that they'd been waiting in drive-thru for unusually long periods of time. The GM goes to see what the deal is, and finds that both the AM and her friend were gone. They'd just up and left in the middle of lunch rush.
It wasn't a case of finally getting the straw that broke the camel's back, either. They'd both planned it. From what I found out later, the week before this, the GM had written up one of the cooks for something. As it turned out, the AM was dating this particular cook. She and her friend planned to walk out and leave the store short-handed in the middle of lunch rush as "revenge".
What makes this even more Sweet monkey fritters!-y is that the previous week, the AM had treated me and the other cashiers on duty to a loud rant, clearly audible to the everyone in the store, on how men of a certain ethnic group were untrustworthy scum, and the cook she was dating belonged to that ethnic group. I could only assume the rant was because of something he did. I guess they made up, if she was willing the throw her job away for him a week later.