Advertising pay sites on "almost" adult sites

Does anybody have any experience advertising adult pay sites on non-adult sites? Theoretically it appears logical that people who visit bikini, lingerie, or wet T-shirt sites are pretty horny are would definately be attracted towards adult sites. Plus, I'd imagine the quality of traffic would tend to be higher because I dont ever see bikini tgp's or lingerie tgp's, and lots of traffic would appear to be from search engines or higher quality traffic sites. However, I've never done this type of advertising myself before and I'm curious what you all think or have done?
Also, would it be better to place hardcore or non-hardcore adult banners on these sites? And why type of site to advertise: one that is straight up-front hardcore such as Kara's Playground or something more teasy such as Amateur Pages?
Thanks,
Kush