Ya.. It is basically anything considered lewd.. But I mean people kiss on the server I heard someone got banned for just kissing someone. But that doesn't mean you need to do a steamy love scene for like 10 minutes of just kissing. Which might be why some people get banned.
It has anything to do with anything related to anything sexual. To be honest, its not that hard to avoid. Pretty much, kiss (cheek/face)=ok, Hug=ok, everything else just don't do and you'll be fine.