Scarlett Johansson's lips are sexily parted. She's wearing a black lacy something. Her eyes? Smoky black and completely "come hither." Photographed by the classically unsexy photographer Terry Richardson, she sexily stars in an ad for Desire, Dolce & Gabbana's newest fragrance. And to celebrate the launch, the perfume team brought in sex therapist Dr. Stephen Snyder to shed some doctorly light on which smells are sexiest.