Breasts.

A young man asks his father, "Dad, how many kinds of breasts are there?"


The father, surprised, answers:


"Well, son, there are three kinds of breasts.


In her twenties, a woman's breasts are like melons, round and firm.


In her thirties to forties, they are like pears, still nice but hanging a bit.


After fifty, they are like onions."


"Onions?"


"Yes, see them and they make you cry."