Wear stripper-style tear-away bike shorts on the way to your presentation. That way you can quickly rip off the sweat-moistened layer without having to take off your pants.
(kidding)
Maybe you could just pull your T-shirt down real far, to cover the butt-sweat during professional presos.
Or wear only bike shorts on the way to the preso and get them as sweaty as you want, then at your destination, put on the dry Dockers over the sweaty shorts for that professional patina.
I'm all out of ideas.