Really had to take a crap badly on the rap down from NF of N Peak of Index a few years back. Was desparately trying to keep the beast contained until we could get off the raps and into the scrub at the base of the route.
I was first on one of the very last raps, the beast was about to escape into my trowzerz, and I just couldn't wait any longer, so I rigged an autoblock and dropped trow while still in mid-rap and in harness. Now you know the reason why the Alpine Bod harness was invented. I have yet to find another harness as light as the AB and where one can remain tied in and drop pants to shit.