I think that I would have also been taken aback by the comment she made. But, instead of wondering what you are wondering about the protection of your boundaries, I would be wondering if they are a couple in trouble?
We don't play with couples in trouble. I can't imagine that I or MR would make a comment like that even joking. It is hard to read the situation as you have read it, but if it alarmed you enough to post, then I think the best thing to do is ask.
I would ask what she meant by the comment. I would look at how they acted when they were together, etc.. If you are stil remotely interested.
If you have completely ruled them out, then you could email her and just let her know that you have changed your mind, wish them well and goodbye.
As a side note, I am curious about something else you commented on; and would offer this advice (I am not sure by your post that you aren't doing this but thought I would mentioned it anyway)
When we meet couples online, through personal ads,at the club, we are very upfront and to the point about our rules, what we are looking for and what we are not looking for. It is only when we are sure the other couple is looking for a similar thing, do we meet them. It is common for the girls to get together for lunch first, and just chat. (that seems to be what we do) and If the girls are interested enough, then usually we then meet couple to couple. Maybe go to a club or out to dinner.
I guess what we learned is to cross the biggest hurdles first (accpetable rules etc) before getting to the point where we like the couple, only to find out we have different rules.
