"So did I have an affinity for ethical non-monogamy as an eight-year-old? Or was I just finding a creative solution to a shortage of Kens???
According to a lot of scientific study, the latter isn't so strange. Even in real life, we do a similar thing. When there are more females and lesser males, the females "fight" for dominance, trying to get "their male". and of course the opposite way, but the former is where the first world societies seem to be right now.
Anyways, because of that, it seems that you'll often find the more dominant sex to often try "spread out, equally", the opposite sex.
Of course, as with anything, there are always anomalies.
and your former point is still as valid too. Just having a natural affinity for it. =] Both can work together well.