Leatheren's answer is the best I've heard in a while, and it's truthfully to the point...if you're wearing underwear, it's for the benefit of people around you.

Something worth pointing out...if it's hanging (the kilt, that is), then it has a greater chance of staying clean. As soon as you sit on it for eight hours, all bets are off.

If you have to climb any stairs, depending on the rise, there is an excellent chance that people behind you will be able to look up your kilt. Consider the benefits of walking up the stairs behind your date, and consider if you want to extend similar benefits to your boss. Same with balconies and the like.

Get in the habit of doing this...hem in front of the chair before you sit, sweep pleats, ***-end moves back and down to ensure the kilt is pulled over the edge of the chair w/o scrunching up. This pretty much guarantees that you will sit only upon your kilt, and if you sit normally (legs apart) and let the aprons settle, you will be completely covered. No guarantees, if you like to dangle off the edge of your chair!

Your kilt will be treated by others the way you seem to treat it yourself.