Here at the Deer Temple we know a lot about being gay, each of us being pansexual. We're therefore able to determine scientifically that deer are indeed very much not straight. This doesn't necessarily refer to their sexuality in itself, as sexuality is merely a human concern and social construct, but mostly we refer to their behavior and look. I mean just look at them!
It is just a fact that boys have a great time together. Pussy is great and all but nobody understands a guy better than another guy, and the same goes for girls and anyone in between too. Deer understand this very well and they're not afraid of being seen hanging out together in dubious situations.
When the Cosmic Deer came up with their list of laws they knew of the beneficial effects of same sex relationships, so not only they allowed them unconditionally, they always encouraged and promoted them, engaging in such acts among themselves too: somewhere very far away, in the deep black space, some magical deer are going at it right now and they care not for heterosexuality. So why the hell should we?
The rate of queer people among deer followers is extremely high and it is not by chance, when you get in contact with these incredible creatures it's hard to stay unaffected, the power of their gayness pervades us before it takes over, turning us into the next stage of human evolution: the pansexual.