FYI: for those who think humans are superior and separate from other primates, here are our cousins:

BONOBO Apes
Bonobo communities are peace loving and generally egalitarian. The strongest social bonds (blue) are those among females (green), although females also bond with males. The status of a male (purple) depends on the position of his mother, to whom he remains closely bonded for her entire life.  Homosexual contact and affection are not unusual.

CHIMPANZEE Bonobo famale sex
In chimpanzee groups the strongest bonds are established between the males in order to hunt and to protect their shared territory. The females live in overlapping home ranges within this territory but are not strongly bonded to other females or to any one male.



GIBBON
Gibbons establish monogamous, egalitarian relations, and one couple will maintain a territory to the exclusion of other pairs.

HUMAN
Human society is the most diverse among the primates. Males unite for cooperative ventures and sexual pairing as do females also bond with those of their own sex. Monogamy, polygamy and polyandry are all in evidence.

GORILLA
The social organization of gorillas provides a clear example of polygamy. Usually a single male maintains a range for his family unit, which contains several females. The strongest bonds are those between the male and his females.

ORANGUTAN
Orangutans live solitary lives with little bonding in evidence. Male orangutans are intolerant of one another. In his prime, a single male establishes a large territory, within which live several females. Each female has her own, separate home range.

The point is that same-sex desire pre-dates modern humans as evidenced in primate evolution.