Well, I had an incident very similar to this about 2 years ago.
I was getting lunch at a major wholesale club, and I happened to drop my car keys accidentally behind me on the floor while waiting for service. I bent down to pick them up and I now was facing away from the counter and what do I see but the white panties of his girl dressed in a white blouse with a blue plaid skirt of a school uniform. I thought I was seeing things so I turned back to the counter, dropped my keys on purpose, and turned around to get an even bigger eyefull; more of her panties showing and with a deliberate widening of her young legs again. I was absolutely shocked at this behavior, with a great deal of titillation on my part. Here was a girl of probably 14 or 15 teasing the hell out of a grown man. I had only read of this sort of exposure, but now I was actually seeing it, not imagining it. I sat down behind her after getting my meal and watched if she would try this on other men, but she didn't because there were no men to tease. Then she got up, walked to the counter, then turned around and walked past me with a tiny smirk on the corner of her lips as she slowly passed me by and she had her eyes riveted to mine. I almost winked at her but I didn't want to trigger an inappropriate reaction from her based on my reaction. But I can tell you for sure, I had quite a few solo in sessions afterwards with her fantasy thrown in for good measure. Very erotic.