My worst ordeal was at a self-serve pump. At KDUA, the line guy (who normally drives the truck) handles the self-serv pump when they're busy with casino traffic or whatever, and three planes can nose in around the pump at one time. Our farm is 2 miles east of the airport and I've been using the airport since 1961, so we kinda know how things work there.
As I'm waiting my turn as one of the three, a Grumman Tiger taxied in and parked in the tie-down area a few hundred feet away and the couple walked into the FBO office. They gave no indication they wanted fuel or service and just disappeared. I assumed they had a car parked outside or a ride awaiting. Not unusual, many gamblers and other patrons do the same.
When my turn (finally) came, the guy said the card reader on the pump was broken so he was using the manual over-ride and I should pay in the office. He said he would push the plane back if anybody else needed fuel, but by then I was the only one in line and the other two slots were open. So I paid, chatted with the FBO manager briefly, and saw the couple in the Tiger emerge from the restrooms and head back towards the ramp.
As I reached my plane to push back, the guy in the Grumann came over and jumped my case for being rude and blocking the pump. I apologized and asked if there was a reason he didn't want to use the two open spots that had been empty for 10 minutes or so. He said he wanted my spot so he could taxi out without being pushed back. I then asked if there was a reason he couldn't use the other outside spot that offered the same access, but that for safety and courtesy we usually didn't swing the prop blast towards the pump guy and preferred to push back instead, which seemed to plss him off even more.
The pump guy was saying all the same things and trying to be nice as well, but the guy wasn't particularly interested in hearing any of them and continued to chew on me.
As I was debating whether to play some offense rather than defense, the pump-guy decided he had heard enough and made it clear to Mr. Tiger that if he wanted fuel he should STFU and put his plane were he was told to put it or go buy it somewhere else. By then I was ready to go, so I left them to continue the discussion without me. A few weeks later the pump guy told me that Mr. Tiger had written a letter of complaint about him to the head of Public Works, who by coincidence has been a family friend since childhood.