As requested in the I2V version, here is the same dataset/captions made for T2V wan. It works great out of the box for non-nude, but it seems to struggle with getting accurate female genitals. I'd highly recommend using HearmemanAI's vagina lora with it to get more detail in those lady bits:

https://civarchive.com/models/2109996/wan-22-pussy-and-anus-lora?modelVersionId=2387016

Prompt is exactly the same as the I2V:

A woman places her buttocks over the camera, obscuring the view. The final frame of the video is a close up of the woman's buttocks and crotch.

And if she's naked add:

The woman is bottomless and her vulva and anus are visible. 

If you're using the pussy lora change vulva to vagina. I find it doesn't move as quick as the I2V one so adding:

The final frame should be nearly entirely black.

Can make her scoot her boot a little faster.