I want to animate a skirt, but whenever the character sits down it slides up and becomes much shorter instead of staying the same length and covering the legs. I want the mesh to change the size as little as possible, only bend and shear. I tried making the Tension/Compression Stiffness very high and Shear and Bend Stiffness low, changing the Bending Model to Linear, making the Pin Group cover the whole mesh etc., nothing works.
And here is the simulation itself:


I'm not sure how clear that is from the images, but the front part of the skirt becomes half as short.

