Even I, who consider myself very open minded, am surprised at what some people do. Most people are at least interested in the topic of kinky sex, even if it's out of their experience. You may also want to try other sites, such as Alt or Collarme. If bdsm is what you have in mind, most cities have local groups which host munches, which are get-togethers, usually at a local tavern.
That said, I think you want to start discussing it, along with sexuality in general, fairly early. You'll find the folks there friendly, supportive, and not evangelistic about their lifestyle. Talk about it before hand,you don't know what he is into until you ask.
The more critical it is, the more important it is to start talking about it early on.
Did you ever give it some thought that just maybe thats the reason he wants to get to know you a little better before sex because he has some perversions that hes afraid to tell you about too.
Think about what chat would be the most interesting for you to get involved in.
Look up online chat rooms and choose the one that best suits you.
If he claims he has never tried certain things,ask if he is willing to be open minded about it.
Is this something I should be discussing now before we get to that point?Make sure you have chosen the adult site you are interested in.