Try again. Lifelong Catholic here, engaged, and I have done a good amount of study on the theology of the body. The Church tells engaged and married couples that every marital act needs to be open to life. Men are not supposed to ejaculate outside of the marital act. Every sexual encounter between married people is supposed to end in/involve the marital embrace--vaginal intercourse. The Church DOES have a problem marrying a couple who will contracept or only ever have non-vaginal intercourse. If the couple does so anyway? It's on their souls. (Trust me: being married in the Catholic Church does not mean you're Catholic. I know far too many people who are married in the Church because their families are Catholic or because they were baptized Catholic but who do not practice the faith, who have no intent to follow Church teaching.)
The Church is not opposed to sex between a married couple, one member of which is infertile, because it is still open to life. The intent is there. The complementarity is there. Homosexual relations are never complementary or open to life. No matter how much you can intend for homosexuals to achieve reproduction by their sexual encounters, they cannot--it simply cannot happen. There is absolutely no sexual complementarity. Heterosexual relations that are rendered infertile by contraceptives (condoms, birth control pills, etc.) or other contraceptive means (sterilization, etc.) are not open to life. These are not compatible with the Church's teaching about sexuality. MarkF makes a perfectly valid point.
"Open to life" does not strictly mean "capable of producing life." "Open to life" means giving reproductive organs and any present gametes (egg, sperm) every chance of resulting in conception--no barriers, nothing that can kill the zygote/embryo/fetus. (This does not mean there has to be a gamete present either--it is open to life to have intercourse when no egg is present, whether before ovulation or during pregnancy, etc.) It means not blocking the possibility and using the right tools in the right ways (penis, vagina). Homosexual acts cannot be open to life because you cannot produce offspring with non-complementary sexual organs/gametes. It's like having two hammers instead of a hammer and a nail when trying to hang up a picture--just can't work. If you have a hammer and a nail, but the wall is cement and the nail can't go in, you're still doing it the right way.
You clearly do not know Catholic teaching about sexuality very well. You should learn more about it before you try to speak authoritatively on the subject.
As a "lifelong Catholic" who's engaged and has done a "good amount of study on the theology of the body," Kim knows what she's talking about, I feel quite sure. And she may well be right that, with an M.A. and Ph.D. in theology from a Catholic university, I still "do not know Catholic teaching" very well.
Even so: hammers? Nails? Really? This is where Catholic moral theology wants to go now to convince us of the intellectual superiority of its claims about the innate moral superiority of heterosexual lifelong Catholics like Kim?
But even taking into account the dullness of this uneducated old head, the head of a non-lifelong Catholic who's also not engaged, I still ask: Hammers and nails? Really?! That's the best Catholics can offer to explain--in all Christian charity, of course, because charity always perfumes everything heterosexual Catholics say to their gay brothers and sisters--why it's fine and dandy for a man and woman in their 70s to marry, or a man and a woman with medical conditions preventing conception to marry, but it's never thinkable for two people of the same sex to love one another?
Because, you do see, don't you, that a hammer never goes with a hammer? It goes with a nail. And a lock requires a key to unlock it. Two locks and two keys don't hang together. And sex between an infertile man and infertile woman is "open to life" even when it's NOT open to life. Just because. Because I choose to say so. It's open to life even when it can't be open to life, when one or both members of the couple are incapable of procreation! Because I, a lifelong engaged Catholic, who declare that a hammer goes with a nail, say it is so.
When a tradition of moral theology that once valued respectful interchange between faith and reason ends up in this place beyond stupidity, where it's all about hammers and nails and using the phrase "open to life" to say the precise opposite of what the phrase means, as if it's a magic talisman: then, I'll freely admit, I don't understand.
And I don't want to understand. I frankly don't want to understand stupidity. I've spent my life trying to get beyond places of stupidity, because, though I'm apparently seriously confused about hammers and nails, I've always assumed there's some connection between using my intellect, reaching rational conclusions, seeking the truth, and finding a God who is Truth.
And there's this: you know the one word that never appears in Kim's blistering and extremely condescending lecture to me about human sexuality and procreation and why people marry? That word is love.
But that word is everywhere in the gospels and everywhere in Jesus's teaching.
And in my untutored way, as a non-lifelong, unengaged Catholic who, as Kim observes, needs to try again, what Jesus says, did, and stood for matters. It matters because, in my untutored way, I have always understood being a Catholic to be all about centering my life on Jesus. Walking in his footsteps. Doing as he did.
Focusing on who Jesus was, what he stood for, and what he did matters, I've always understood as a non-lifelong Catholic, more than hammers and nails and cement walls. And it matters more than lying about openness to life in church-sanctioned heterosexual relationships that can't be open to life--lying to sustain an insupportable, astonishingly cruel, and unjust ethic of heterosexual superiority that has nothing in the world to do with anything Jesus ever taught.