i had a js load script open so i made a quick load checker. it just checks if its possible to load a url into a div using 'load'. i get cross-origin notices for most domains. you can switch to https to test one of those.
porn-update js load check
(i tested with
Yukis Vault - PornCMS Bonus Site Updates)
if you think they're using iframes, that's pretty easy to check.
Free iframe checker | TinyWebGallery Blog
if its something else, post what you need and someone can offer a possible solution.
#porncms