I met poly in Stranger In A Strange Land, by Robert Heinlein. I read it the first time before I was 13 (in the very early 70's), but I don't remember exactly when the first time I read it was. My parents made some attempts at poly relationships, but they weren't exactly including me. Didn't know the whole story then (and I'm not certain I do now).
My first personal experience with poly was in my twenties, with a woman who was flirting with both me and my girlfriend, while gf and I weren't telling each other that was going on. We later found out she had a history of doing this with couples. We attempted, for like a minute, to have it be the three of us. At some point in that, I got a black eye out of it.
I didn't much think about it, until it presented itself last December, and here I am in my vee.
Love is that condition in which the happiness of another person is essential to your own...
Robert A. Heinlein
Me: female, bi, (formerly hinge of a vee)
with FirstBoyFriend (FBF)(moderately long-distance)
and no longer with CurrentBoyFriend (CBF)(who now lives in a house far away-with stairs I can't climb)