We kind of fell into it in a fashion. Intense friends with two guys, deep crushes on either one on any given day and, despite a very provocative dream I had early on, the sworn decision to never act on my feelings for fear of ruining the friendships.
Until one of them acted on his and the other one felt like his whole world was going to fall apart. Two months later, after hours of talking and negotiating and really plumbing the depths of who we are as human beings, we figured we'd try a polyfidelity situation because maybe, just maybe, that would save everything from being the end of the world.
Weird thing? It did. I doubt I'd be "poly" with anyone else but these two.