I don't know about your lower butt cheek, but mine and, I presume from the testimony, Davila's is below the pelvis. I don't know about yours.
See that hump which is lower than the pelvis on the right of each person in the image above. That is a butt cheek. Where it meets the leg on the legs way down to the foot is called the lower butt cheek.
I do not think that the "image above" is what you say it is.
Also, maybe I do too much running and stuff, but my butt does not sag beneath my pelvis - it pretty much ends at my hip socket.
And yes, I am aware of how bizarre this conversation is becoming.