Here's a LoRA for those willing to sneak a peek. You get to see both the girl as well as a look under the skirt.

• Color consistency between the panels is a bit hit and miss; it helps if you manually specify the color of the skirt/dress.

• Prefers landscape format for obvious reasons

Overall I'm quite happy with the results.

Use a prompt like:

{describe the lady}, wearing {dress/skirt/whatever you prefer},(splitupskirt, upskirt, split screen, panties) <lora:Upskirt_Split:1.2>