A woman walks into the drugstore and tells the pharmacist she wants
to buy some arsenic.

"What do you want with arsenic?" asks the pharmacist.

"I want to kill my husband because he's cheating on me by having sex
with another woman", the lady replies.

"I can't sell you arsenic so you can kill your husband, lady, even if he is
having sex with another woman", the pharmacist says.

The woman then reaches into her pocket and pulls out a picture of her
husband having sex with the pharmacist's wife and hands it to him.

"Oh, I didn't realize you had a prescription, the pharmacist replies."