/3/ - 3DCG

>>918649
That looks like it would conform to the shape of the dong a lot better than the approach I found.

For some background info on this approach, you set up some bones with the 'limit distance' constraint bound to another bone, 'Pusher' in this case, and 'Clamp Region' set to outside. You can also add the 'Limit location' constraint and limit all but the local Y axis to 0 so the bones will only go up/down their local Y axis.

You can then set them up to increase/decrease their distance with the scale and position of the Pusher bone.

It's probably easier to follow this video, just be aware that Blender's interface has changed since.
https://www.youtube.com/watch?v=0wzCZZ69l3I