By Chip Rowe

As I compiled Dear Playboy Advisor, which includes 800 of the most entertaining and provocative questions of the past decade, I browsed through similar collections published in the 1960s, 1970s and 1980s and dog-eared a number of pages. Here, then, are the 20 most memorable sex questions and responses that have appeared in the Playboy Advisor since its debut in September 1960. You may have your own favorites.