Alan, please don't take this the wrong way, but when you say that you figured that adults had it "more together," you are admitting to a certain amount of naivete. Please....., jerks come in all ages, sizes, shapes, and colors, (just look at my in-laws.) Just wear the kilt proudly, know who you are, and let the negative stuff roll off your back. It's not our job to educate the world, (although I gather by your post that you are a school teacher,) ("our" meaning the kilted ones.) If you want tolerance, then tolerate others, even in their ignorance. You won't change a thing by staring down or confronting every negative remark or whistle. These guys weren't interested in learning about kilts or your scottish heritage, they just wanted to get under your skin, and you let them. I'm sure they all had a big laugh once you were out of earshot. If you're wearing a kilt, you're bigger than that.
Respectfully,