In the midst of a continuing heatwave, my sister, unable to bear the heat, came over with her female classmates to play in the water in our garden. They were playing carefreely and her skirt flipped up, revealing her panties! Moreover, their excitement escalated to the point where their bras became see-through from being soaked through! Watching this scene, I couldn't help but stare, unknowingly getting an erection. I thought they would notice and be disgusted, but instead, they found my erection amusing and proceeded to even more provocatively display their wet bodies and underwear, making it impossible for me to hold back…
