There was a mother that had a daughter, Mary, 
that always sucked her thumb. Upset by this, 
Marys mother told her that if she continued to
suck her thumb, her body would swell up. 
Frightened, Mary stopped sucking her thumb. One 
day Mary and her mother were crossing the street
and Mary saw a prostitute with big breasts. Mary
pulled away from her mother, walked up to the 
prostitute and said, "Lady, I know what you've
been sucking"