Cheetahpaws's patreon reward for January 2019(though I think it actually got published around March, not January?). The pack also contained steps/sketches/drafts of this sequence, which this gallery unfortunately does not include. The final image in the gallery (img #20) is a brief animation version of the work(its available publicly) however, its censored, and I think the uncensored version was only available from the original distribution via DMs on patreon. The Seth orgy pack(at the time of writing) is also available to purchase from the artist's gumroad. Note: the pack says that it includes 20 variations, but one was just a smaller version of an existing variation, another was a censored version of the aforementioned smaller image, and another which was seemingly an exact duplicate of page 10.
Also note the artist's patreon seems to be under an indefinitely lasting review.

Also, I know this Seth is from TAS and the figure in the top left is probably Tadatomo, but I don't know who the others in the image are, assuming any of them are also TAS characters.

Artist's links:
https://cheetahpaws.carrd.co/
https://www.furaffinity.net/user/cheetahpaws
https://twitter.com/Cheetah_paws(NSFW)
https://twitter.com/ArtCheetah(SFW)
https://trello.com/b/l21ahZIk/commission-queue-2024-cheetahpaws
https://gumroad.com/cheetahpaws