Would cohesive butt implants retain their shape after they've settled? I'm skinny so, I'm worried about the solid types offered in the U.S. showing through my muscle/skin even after it's settled. My main issue with the cohesives is that since they're more "soft", it won't be able to retain it's shape which may or may not make my butt look saggy. Any thoughts? Even a pros and cons list to each type would be great. Thanks.