I am bisexual. Back in the day, I thought it would be lovely to have a couple. My experience back then was with men who had way higher sex drives then I did. I thought if I shared a man with a woman, it would work out to match my drive better, and I wouldn't have to be the only one satisfying him. Although I probably imagined her a dynamo, because I would have enjoyed sex with her too.
A hundred years later, here I am in a vee with two men. One of them is slightly long distance; and both of them have much lower sex drives than I do.
But I love them both beyond reason. I fell in love with both of them after being friends with both of them. (long story can be found elsewhere, life stories and blogs)
I think that's why I wasn't in poly before. I wasn't seeking out a configuration, but these two men showed up and I was ready.