[osreb]

A wife asks her husband, "Would you please go shopping for me and buy one carton of milk, and if they have avocados, get six."

A short time later, the husband comes back with six cartons of milk.
The wife asks him, "Why did you buy six cartons of milk?"

He replied, "Because they had avocados."

(If you're female, you'll probably go back to read it again. Males will get it the first time.)

Makes sense to me!