My best is when I was in middle school. It was a private school so girls have to wear skirts as part of the uniform. This girl always wore shorts under her skirt the previous year. Fast forward a year later... It was morning and we were getting ready to start class. She arrived to school and then bend down to tie her shoelaces. As she was tying her shoes, I noticed she had white panties on. I stood there as she tying them shocked. She always wore shorts the year before, maybe she forgot to wear shorts today. The next day, she was wearing just panties again.
It was like that the whole school year. Unlike the other girls, she was very easy to look up
She mostly sits down with legs wide open, legs not fully crossed, sitting on the floor with her knickers exposed, playing basketball with her skirt flapping up as she shoots or spins hard, etc. She would sometimes wear shorts later in the school year, but she was very careless since I can still see her panties underneath.
The best view was the end of school. We were getting ready to go home and get our books and stuff, and her desk was next to mine on the right. I decided to sit on the floor to get my books out as she was standing up putting her stuff in her backpack. I moved foreward and I saw for what seems 30 seconds... I saw her butt- she was wearing white panties with multi-color dots on. I had to stop when one of my friends started to ask me a question. She always had three types of panties on throughout the year: white, white w/stripes, white w/dots. I still get hard when I think of her.