Sure, external factors can lead to homosexuality. Doesnt change homosexuality still ocurring naturally in humans and other non-human animals
Animals are involved in:
Necrophilia : https://www.sciencealert.com/10-delightful-animals-you-may-not-have-known-were-necrophiliacs
Eating poop - Coprophagia: https://en.wikipedia.org/wiki/Coprophagia
Cannibalism: https://www.discoverwildlife.com/animal-facts/cannibal-animals-creatures-that-eat-their-own-kind/
So, using animals as an example is straight up stupid and retarded.
Find a better justification.