LEE was working on this as one of two optional poses for a Skeb request he was working on months ago. In the end he settled the pose for post #5431560 and this one got shelved. Possible he had planned to finish this one but became busy with other projects, he did start work on a new Animal Ear Hot Spring book shortly afterwards.

Edit:
Interesting. It seems just one day after I made this comment about second pose being shelved LEE makes a post on Pawoo saying he plans to finally finish it.