Well, if we're discussing Ancient Egypt, let's not forget the story of Set and Horus, where there's an incestual homosexual affair between them (uncle and nephew) and Horus impregnates Set. I'm not sure which time period that story belongs to... perhaps someone can comment.

As to homosexuality... there's a number of cultural practices that border on it in ancient cultures that survive to modern times (look up "flute practices"... yes... that's what the squickly anthropologists called them.) Sparta, famously, encouraged it and it was not considered an outrage in ancient Greece.

Group masturbatory activities among males are common in many areas of the world. In samaurai Japan, male "geishas"/lovers were considered a bit of a scandal but they did exist.

Some of the Eskimo cultures practiced polyandry, where a woman would have two men she lived with and undoubtedly they had what would be considered homosexual/bisexual activity in some of these groups.

But we know these only from living cultures and written records. When some one is born homosexual, there's no marker on their bones that separates them from any other human, and they can always father children or bear children (lesbians.)