Too many webmasters take the warning page too literally and I think you have as well. Also, it is common for webmasters to seek out new marketing methods without getting their core proposition tight.
Even though it is a warning page, you still want visitors to click on the "Enter" link. Your challenge is to get them to click through so they can properly evaluate your site.
Let's park the header design for a sec. There is nothing on your entry page that tells a visitor what's in store, how you are different and why they should enter your site.
Don't take my word for it, if you have Google Analytics installed just check your bounce rate off your index page. If it's 30% or more, you have an issue.
On the proposition contained in your header, experienced porn surfers perceive a difference between the fetish niche and the BDSM niche. Which one are you?
__________________
|