MY BUTT IS BIG
AND ROUND LIKE THE LETTER C
AND TEN THOUSAND LUNGES
    HAVE MADE IT ROUNDER
             BUT NOT SMALLER
                   AND THAT'S JUST FINE.
                          IT'S A SPACE HEATER
                                FOR MY SIDE OF THE BED
                                       IT'S MY AMBASSADOR
                                         TO THOSE WHO WALK BEHIND ME
                                         IT'S A BORDER COLLIE
                                         THAT HERDS SKINNY WOMEN
                                   AWAY FROM THE BEST DEALS
                             AT CLOTHING SALES.
                      MY BUTT IS BIG
              AND THAT'S JUST FINE
        AND THOSE WHO MIGHT SCORN IT
        ARE INVITED TO KISS IT.
                              JUST DO IT.

I found this in one of my fitness magazines and it was a Nike ad to women. Love it!