How to catch a unicorn

That's a good question, but I think the idea of a "unicorn" goes far past a simple threesome or date. In my experience, the first-time threesome is often driven by my partner finding someone they see as "disposable"... They want to try out the threesome without fear of a continued relationship between the other girl and me. To me, a unicorn is that person who DOES stick around for future fun, so I think "finding a unicorn" is just about an open exploration with your partner for someone you both enjoy. I don't know what it feels like from the potential unicorn (what they're looking for, what turns them off, etc.), so I'm curious to see what others have to say here...