It's too bad they don't have KEYWORD blocking, but you still have to keep up with stuff like this. People have been requesting keyword blocking for years. For now you should add that site to your filter list. It's a pain to do it site by site, but it's worth it for reputation's sake since people might think YOU (danroth) are advertising a dating service, which is another misconception about AdSense. I spent time weeding out most of them, but when one is discovered it only takes three minutes to add it to your site-blocking filter for AdSense.