Not a major peeve, but I thought worth a hoot:

At the Celtic Fling in Lancaster, PA last year, I was strutting along in my Thompson Grey casual from USAK and a black t-shirt with "Real Men Wear Kilts" in white letters on the front. I noticed a fellow wearing the same shirt walking towards me in the crowd. As he came close enough, I saw his lower half was covered by...
Wait for it....
Bermuda Shorts.
I guess he was making some sort of statement.

I saw this guy too. My wife couldn't understand why I was shaking my head ...

Maybe he'll be in proper attire this year.