The Sims 4 butt slider is pretty easy to use and understand.
These butts are a lot more natural-looking than those in the CAS options. You will get various types of sliders that will edit different parts of the butt of your Sim. This will give you complete control and let you entirely customise your butts.
With the help of this big booty cc slider, you can make the butts of your Sims a bigger booty or a smaller one, rounder, flatter, etc.