A woman goes into a pharmacy, She says to the pharmacist, "I'd like a poison that will kill my husband but make it look like he died of natural causes."
The pharmacist says, "Ma'am, not only can I not do that for you, I'm going to call the police and report you."
The woman takes out something out of her pocket and hands it to him. It's a picture of her husband having sex with the Pharmacist's wife.
"Oh, you should have told me you had a prescription."