I made this in my own animation program that I'm developing. It's very smooth because it's vector based with automatic interpolation. It's a bit tricky to animate lines that aren't visible in every frame with that system though, and I didn't really have the tools to fix things coded at the time, so I just sort of stopped.
I think a good way to do it might be to make everything see-through like you'll see in the next animation. I'll work on layering strategies once I get coloring added in.
Well, the labia, much like the foreskin, is movable, perhaps his glans (bottom of the penis head's "mushroom") is wide enough to pull on her lower lips
Allison is by far my favorite of all of your characters -- love seeing the gradual progression of her hopelessly inescapable descent into sexual slavery!
I love the extreme shift in perspective in the two frames of this panel -- especially seeing the heft of Allison's enormous mammaries from below like in the lower frame!
