Same-sex sexual behavior observed in dozens of primate species, suggesting evolutionary origin

[Coventina]

6. I read somewhere (too lazy to try and find source right now) that in early humans

Most of the males were the "father figures" to their sister's (or sisters') children.

The women would breed with whomever they chose in the moment, but their children were reared in a matriarchal structure where their uncles were the "dads" (protectors and providers).

This is thought to be possible reasons why so many romantic relationships are intense but short-lived, and that long-term monogamy is really something that has to be a central focus of effort.

So the "guncle" (gay uncle) may be a very ancient archetype indeed!