A family is at the dinner table. The son asks the father, “Dad, how many
 kinds of boobs are there?”
The father, surprised, answers, “Well, son, a
 woman goes through three phases.
In her 20s, a woman’s breasts are like
 melons, round and firm.
In her 30s and 40s, they are like pears, still 
nice, hanging a bit.
After 50, they are like onions.”
“Onions?” the son 
asks.
“Yes. You see them and they make you cry.” This infuriated his 
wife and daughter.
The daughter asks, “Mom, how many different kinds of 
willies are there?”
The mother smiles and says, “Well, dear, a man goes 
through three phases also. In his 20s, his willy is like an oak tree, 
mighty and hard.
In his 30s and 40s, it’s like a birch, flexible but 
reliable.
After his 50s, it’s like a Christmas tree.” “A Christmas 
tree?” the daughter asks. “Yes, dead from the root up and the balls are 
just for decoration.”