Conundrum

I have held a professional job for the past five years. Over this time, I’ve built up a wardrobe of rather boring and conservative work-appropriate clothes. Given that it’s wintertime, I’m usually covered from my neck to my ankles these days… at least while I’m sitting at my desk. When I’m teaching, I’m standing and I raise my arms a lot (to point to my hair when reviewing vocabulary for body parts, to write on the whiteboard, when I say “raise your hand if…”, etc.). When I raise my arms, ALL of my tops (I may or may not have tried a few on just to prove my point) have a tendency to rise up too, exposing a sliver of flesh above my pants. According to some, this is inappropriate and unprofessional. What should I do about it? Here are some options I’ve come up with:

1. Nothing. This is America. Nudity is everywhere. Students will have to get used to it sooner or later. 
2. Keep one hand hovering around my waist at all times to block unseemly flesh flashes and constantly tug my shirt back down. 
3. Invest in some tee-shirt extenders. These are usually marketed for pregnant women, but I suppose they would get the job done. 
4. Break the bank and immediately replace my wardrobe with tunics, overalls, jumpers, dresses, and seriously high-waisted pants. 
5. Safety pins, safety pins, and more safety pins. 
6. Never raise my arms again.

Do you have any suggestions? I’d love to hear them.