Cassandra was my.... what is the word?.... i would say "girlfriend", but that wouldn't go far enough.  I would say "wife", but people would think that implied strict monogamy and involvement by the church and state.  I would say "partner", but when i would say i have a "partner" in the Bay Area, people would asked "What's his name?"  I used to use "SO" for "significant other" but that's kinda awkward.  "Companion" is too vague.  If i was speaking to somebody likely to have heard of polyamory, i would  have described her as my "primary."

Back when we began dating, this was my blurb for her:

Cassandra is... an overeducated, bohemian, east-coast wanna-be geek.  We share cultural values, intellectual interests, and a lack of personal boundaries.  Her personality is hyper-kinetic, exciting, turbulent, and adorable.

We first met standing in line for a rave in March 1998 at the Maritime Hall in SF, at which time we both had other relationships.  A couple months later we (then single) bumped into each at a screening of Modulations at Stanford, a documentary on the history of electronic music.  I gave her a ride to a Koinonea rave in Oakland; we danced like mad and cuddled in the chill space; and the relationship had begun.

By 2002, after we had been living together for a couple years, we started drifting apart.  She developed interests i didn't share, like watching sports in bars.  She started seeing another guy (i.e. she left me).  I moved to New York, she stayed in San Francisco.  We've stayed friends.