You are looking for a unicorn? Have you done a search here for "unicorn" in the tags? Go to the search engine and have a look. I would start there. To me there is nothing like reading other peoples stories to see how it could work out.
There is a lot of couples looking for a bi woman to join them... good luck. I have never known one single time when that has worked out for the long haul, past the initial sexy NRE time. Triads that work seem to be built out of friends that all grow into it or couples that are very independent and are able to accomplish having other partners that they either share or don't...
Sorry to be a downer about this, but I hate to see couples go to so much effort for an illusion. What you are looking for seems to be just that.
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