You'd be surprised actually, because most of the (sexual) art on FurAffinity and other furry-centric websites is depicting female characters and heterosexual sex. While males and gay sex are certainly very common, probably a lot more than in most other genres, they still are in the minority.
Almost all of the most popular furry artists either only or mostly draw straight/female art, and very rarely do gay art, if they do any porn at all. This kind of falls in line with the fact that most of the furry fandom are bisexuals, and the second biggest group are straight, while gays are still in the minority (this is not coming out of my ass, by the way, but correlated by several studies of the furry fandom; though granted, the spread could have changed by now but I don't think so).
The reason the furry fandom towards the outside looks very "gay" is because there's more men than women, most of them are bisexual, and relationships tend to stay within the fandom because of social ostracization from many other sub cultures, so there's a lot of male/male relationships. Couple this with the openness about sexuality and you have this image that everyone in the fandom is gay, while it couldn't be further from the truth.