It’s the oldest truism in the book: Sex sells. At least that’s what the folks at HBO and Showtime are banking on. Both pay-cable networks are currently shooting new erotically themed weekly anthology series, scheduled for airing early next year. HBO’s will be called The Stranger; each episode will tell a different tale of love and lust set in Paris. ”They’re sort of like half-hour versions of Last Tango in Paris,” explains producer Lewis Chesler, who also created the original The Hitchhiker for HBO, one of cable’s first R-rated series. ”They’re stories of identity and anxiety, told through an erotic crucible.” In other words, expect lots of nudity and explicit dialogue. Showtime’s half-hour series, Red Shoe Diaries, will take a peek into the pages of a different woman’s secret diary every week. The show’s director is Zalman King, producer of 91/2 Weeks and Wild Orchid. ”I’ve had more freedom with this show than I’ve had with my feature films,” King says. ”I don’t have to worry about the MPAA. I don’t have to cut scenes to keep an R rating. With Diaries, the audience will have a chance to see my original intent.” In other words, expect lots of nudity and explicit dialogue.