Well, I laughed when I read it:
A lady walks into a drug store and tells the pharmacist she needs some cyanide. The pharmacist asked, "Why in the world do you need cyanide?"
The lady explained that she needed it to poison her husband. The phamacist's eyes got big and he exclaimed, "Lord have mercy; I can't give you cyanide to kill your husband. That's against the law, and I'll lose my license, and they'll throw both of us in jail, and all kinds of bad things will happen!! Absolutely not, you CANNOT have any cyanide!!!"
Then the lady reached into her purse and pulled out a picture of her husband in bed with the pharmacist's wife.
The pharmacist looked at the picture and replied, "Well, hell, you didn't tell me you had a prescription."