I was on a UA Airbus 319 last week in Row 2 F flying SJC-ORD and had a little tiff with the guy sitting next to me. Wondering what you all think...

You know how there are three "compartments" under the seat in front, one on each side and one in the middle, separated by metal bars. My seatmate, who had boarded first and was sitting in 2B had taken up the middle compartment completely with a rather large briefcase. So after putting my laptop case under my third, there was really no place to put my legs.

I asked him if he wouldn't mind either turning his briefcase a bit to give me a little more space, or put it in his side, or put it overhead, as, again, it was somewhat on the large side. His response was simply, "Sorry I won't," with no further explanation. I didn't push it, but it wasn't the most comfortable 3 hours.

I'm not sure what the etiquette is here, but out of courtesy, I usually keep my carryons.