A previous housemate was a professed and practicing homosexual. I say the latter because I got to know him well and became convinced that he was not really a homosexual at all. He had been engaged to a woman who dumped him and his mother was a paranoid schizophrenic. He was a mess who hated himself and thought he was not worthy of a woman's love since his fiance had dumped him and his mom was crazy. He actually had a female friend who fell in love with him, and even got him to sleep with her. He was incredibly promiscuous and went to all the bars. He used to love to come home and tell me who he saw at the bar (we lived in Washington, D.C. and you might be quite surprised at some of the names.) But he was one of the unhappiest people I have ever met. He eventually died of AIDS.
I have eight former friends who died of AIDS. When I look back on them, they were all the same, unhappy men who hated themselves. I have a close relative now who claims to be gay. He is 45 years old and still will not tell his parents. He has a "partner," but since he came out to some of us in the family he has been even more unhappy than he was before. He has gained weight, developed ulcers, and is generally a mess. He jumps from job to job thinking that will make him happier. I think he just hates himself and the homosexuality is a form of self-abuse.
I have concluded that there is no such thing as "homosexuality." Many people have sexual attractions and feelings of love for people of the same sex from time to time. This does not make one "homosexual." God designed human sexuality for one reason, to result in procreation and propagation of the human race. All people can find true happiness in this way with a partner of the opposite sex. Fulfilling only the transitory sexual attraction does not lead to true happiness. This is why so many "homosexuals" are unhappy and unfulfilled. Others who call themselves homosexuals are engaging in sex with same-sex partners strictly as a form of self-abuse, because they have deeper emotional problems.
In some ways, the Catholic Church had it right back in the old days in Ireland, when it was a sin to have sexual relations outside of marriage, and a sin to have it even with your spouse unless you were making a baby. The mistake was that the Church used only punitive measures to enforce this, and was too embarrassed and puritanical to teach people frankly about sexual desire and the importance and Godliness of overcoming it.
The part I don't agree with is your idea that it's a sin for even a husband and wife to have sex if they're not trying to make a baby.
This is not, and never has been the teaching of the Catholic Church (though there were douibtless some Jansenistic Irish priests and nuns who said so.) At the very least, marital intercourse was always seen as a "remedy for concupiscence" ("It is better to marry than to burn" --- St. Paul) and as an act expressing the unitive (bonding and belonging) meaning of marriage.
Pope John Paul II went a lot farther than that in discussing the mutual self-giving of marital sexuality as an image of Divine love --- whether or not the couple are physically capable of pregnancy.
And I think Pope John Paul was right. There's a depth of meaning there, for those who are spiritually able to discern it.
Well worth repeating!