Pornography is more abundant and accessible than ever before. So it probably isn't surprising that it appears to be having a greater impact on romantic relationships. This week, the Sugars begin a two-part series on the topic. Part 1 focuses on some basic questions about porn -- is it wrong to use it? Why do people turn to porn? Is there such a thing as "healthy" porn use in a relationship? They discuss with the help of sex therapist Wendy Maltz.