Sexually explicit sites are sensitive topics. You have a site, it ranks well for specific keywords, but there are sexually explicit content and/or images on the pages. It is preferred to have an entry page for a first time session on the site. But that doesn't really sit well with search engines. One member at Cre8asite forums started a thread named SEO'ing past 'sexual content' disclaimer. In this thread he asks about putting a disclaimer on each page or redirecting all first time visitors to an entry page with the disclaimer.
Forum admin Grumpus recommends that he add an ICRA Label to his site. He warns that this label will most probably exclude the site from the default results, with safe searching on. Black_Knight says a disclaimer has no legal strength, but a "PICS label or ICRA label are the best legal defences right now." Ammon Johns PMed me with a response, "Those online disclaimers really aren't worth a thing when the whole focus of search engines is to deliver you direct to the content, not the disclaimer." Yup, yup.