This month's Fleshcult update will introduce The Tome of Rumps. You'll be able to give the protagonist all manner of butts: plush bubbles, firm muscles, subtle slender asses, and great big pear-shaped bums. Some will enhance the bottoming option. Others will open up a brand new face-sitting option. Just remember to lift up before your partner runs out of air!
I'm going to also see if I can fit in some quality of life improvements, but for the most part, this will be a butt-themed month.