Arsenic
A woman goes to the pharmacy and asked the pharmacist for arsenic.
The pharmacist asked what in the world she needed Arsenic for.
The woman replied that her husband had been unfaithful and she intended to poison him.
The pharmacist replied "Ma'am, there is no way I am giving you arsenic."
The woman reached into her purse and pulled out a photo
of her husband and the pharmacist wife in the process of having sex.
The Pharmacist studied the photo for a moment, looked at the woman, and said, "Why didn't you tell me you had a prescription."