I'm small in the front but i'm hiding something in the back

Small in the front but not in the back

small in the front, but thick in the back

small in the front, but thick in the back

small in the front, but thick in the back

small in the front, but thick in the back

small in the front, but thick in the back

small in the front, but thick in the back

small in the front, but thick in the back

small in the front, but thick in the back

small in the front, but thick in the back

I'm small in the front but not so small in the back! Hope you