Buttocks of the tender type.

I theorize that your butt should be more tender the younger you are. It only makes sense right? I mean your feet and hands usually tend to callous as you use them more and get older. But the butt is the complete opposite of what it should be. I used to be able to ride my bike all day long and not have any problems but today after a 3 hour ride with the boy, my buttocks are sore!! It us just not fair!