If that was the case, how come the same thing doesn't happen to women, or any other loveually reproducing organism in existence
First off, animals in the wild wouldn't be reproducing in their habitat if they were actually homoloveual. There's no way of knowing if there are other species that contain homoloveuals.
Also, to the statement quoted: It might be true. It's possible that only the human species contains gays. Then again, no other species evolved brains capable of extremely sophisticated thought and computation. No other species built civilizations, computers, cars, or even a system of society. No other species has developed the technology to travel to space.
We are different from any other inhabitants of Earth. It makes perfect sense that we could have distinct differences from animals, like homoloveuality, that defy the normal laws of nature.
TL;DR: We don't know if there are gay animals, and we're different from animals. It would make sense that only our species contains gays.
