I have no disdain for Christians in general, only for fundie assholes, and I'm Pro-Human-Rights.
Heterosexuals manage pretty well being licentious and promiscuous too, ya know, and in much greater numbers.
Homosexuality is neither a sexual function nor a sexual act, it's a sexual orientation. Sexual acts, on the other hand, can be used by both gays and straights alike, and by bisexuals too.
My biology showed that sex is for comfort, bonding, closeness, relaxation, enjoyment, oh and procreation too, but that's just in a very small amount of sexual encounters. Human women have constantly swollen mammary glands because that made our male ancestors stay longer with the same female, which gave their children a better chance for survival. I.e. we humans survived and prospered because we like sex.
Darwin has been dead, what?, about a hundred years; he's not nodding in any direction. He's probably just dust by now.
We did do the math; no homosexual couple has ever had a child by accident; their children are all wanted and fought for. Teenage pregnancies, on the other hand, seems most rampant in strict Christian communities, often with abstinence-only education in school. And, I hear that anal sex is more common between these teenagers than it is between homosexuals. What did you say about promiscuity again...?