Unintended Consequences: The downside of Viagra:

"The other thing we've learned is how important the erect penis is for a woman's sense of her own sexual appeal,' Morgentaler says. 'When a woman finds out a man has been using the pill secretly, there are two main reactions. One is fury about the dishonesty aspect and the other is, 'I thought it was me that was turning you on. Why do you need a pill to have sex with me?''