I think what the OP misses in the first place is that there are somethings you don't have to try to decide that its not for you personally. I for one have no desire to jump out of a perfectly good airplane, yet there are those who skydive. Personally the whole thing causes my stomach to do dry heaves, but hey that's just me, to each their own.
As long as everyone is in agreement as to who can do what, to which and to whom, it does not matter what other people think of their beliefs. Thus although bicurious, Mrs. bi and I respect that the other couple may not wish to do this and thus would not force them to do so. Just as we would expect them to not push their preference for strong D/s on us.
If the mere fact we list ourselves as bicurious causes a purely straight couple to reject us, then it is their decision and no loss to us. They may miss out on a perhaps truly wonderful time and so do we, but those accept us as us are out there as well. I'd rather play with them and respect their ground rules than worry about what they will attempt. I will deal with that when it comes.