One more thought is that the idea of joining a group or going to events sounds more "serious". If he is only interested in the lighter aspects of BDSM, perhaps he thinks these events cater to the more hardcore aspects of the lifestyle. In which case your interest could be mistaken as you wanting more than you let on.

I know I was intimidated as all get out before the first munch I went to, and even more so before the first party. I actually got to the meeting area almost an hour early to make sure I was dressed right and that nobody looked too scary before I could work up the nerve to walk in.

Good luck with your playmate, I hope it works out and you both find what you are looking for.