Elephant Butt

Great googly-moogly, look what happened when I wore Pattern Project #3 for a day. Can you believe the wrinkles? Whatever this is, I think maybe tencel or silk, it is the FABRIC OF THE DAMNED. Thank goodness I was wearing leggings or I would have been mooning people by the end of the day thanks to that seat crease.  Sewing ladies and gents, what to do? Please feel free to expound beyond the limitations of the survey over in the comments!