By all means. Rumps.... stay upright. If you can be completely sure of that, all safety gear concerns are taken care of.

<stepping on soap box>
I can tell you from personal experience that cordoury(sp) pants, and a tee shirt are not very effective at avoiding road rash. Sneakers, either.
My summer weight gloves? Same ones I wear 3/4 of the year.....leather over the wrist gauntlets, with insulation, and doubled leather in the palms. There's no way I could pick up a coin off the street in them.... I'd never feel it. I'm okay with that.
That pair, the armored jacket, FF helmet, steel toed over the ankle boots, and blue jeans kept the injuries on my next crash limited to 3 broken ribs, and a seperated sholder. Had a bruise on the inside of my knee the size of a dinner plate from the 'pod' running my leg over as the bike slid through.
No abrasions at all. Scuffed up helmet (retired). The rest of the gear still sees daily use.
Deep winter, I switch to ski mobile gloves. Not as protective.... but so much warmer, I am willing to accept the compromise.
The absolute best piece of safety gear any rider has, sits at the top of their neck... roughly 7lbs of fat in a convenient carrying case. The better we use that, the less need there is to test all of the 'back up' systems.
By all means, stay upright, my friend. .02