I'll admit!
I've been riding with the same group of people for a number of years. Depending on who I ride with, I'm at varying points within the pack.

Fair enough.
One ride, was riding behind my friend who happened to have a ZX10. 3 boys behind us (who I'd never met but shall forever be known as The Russians) decided that they didn't like riding behind girls. Keep in mind we were near the front of the pack in a fast group.
We pull up to a stop sign and I hear them say something about "riding behind the bitches"
I'm very non-competitive but it was enough to piss me off a bit.
Next set of twisties, first Russian (the one directly behind me)....pulls out on me in and then proceeds to block me into a corner so his buddies could get past.
Like I said...not competitive but I lost it and rode like a complete maniac for the next little while just to
show them.
By the time I had significantly shown them I'd cooled down enough to realize how stupid I was being.
They couldn't ride for shit and it didn't take much to get back up in front of them....but it was a stupid move on my part.