By private discussion group I was thinking an invite-only forum could be set up off BL. For example I could get such a thing running in about an hour on my server. I suppose access would need to be arranged via PM, and it's true, it could all be done on PM, so it's probably not worth the hassle.
Just it's easier to discuss things on a discussion forum as opposed to PMs, especially when there's a fair few people.
gayorstraight, BHM deleted the kink thread, as his right, apparently, as thread starter. Not a right I think is valid after a discussion has kicked off, but that's how it works.