Grandpa found Viagra in his son's medicine cabinet and asked if he could try one. The son said, "I don't know, they're very strong and expensive." "How much?" he asked. “£10 a pill,” the son said. "I don't care. I'll try one, and leave the money under your pillow.” The next morning the son found £110.00 under his pillow. He tells Grandpa, "I said each pill was £10.00, not £110.00." "I know, Grandpa replies, "the £100 is from Grandma.!!!