Aquinas ... to characterize homosexual desire and love as a cancer leads you off track.
There is not anything at all sensually superior in one form of sex over another. It all pretty much comes down to the burden we all have to bear, the hormonal combined with the tactile.
The bigger picture when contrasting homsexuality with heterosexuality is procreation. That is a significant consideration.
But the other bigger picture is affection ... who stimulates our basic selves.
Some people are just as naturally attracted to the same sex, as others are to the opposite. There is zero advantage to desiring a person of the same sex, and probably a risk of huge disadvantage.
For homosexuality to be condemned, even the act to be condememned (beyond the condemnation of non-marital sex itself) requires you to identify some harm to the act itself.
Heterosexual sex can be condemned on the grounds that a child might be reproduced, irresponsibly.
What is the essence of the sin committed by homosexual sex?
Ok, you claim (apparently) that there is nothing intrinsically wrong or harmful about same sex acts. You are singularly ill-informed considering that you have been registered as a FR member for several years.
Here's a link to the Categorical Index of Articles about homosexuality in all its aspects:
http://www.freerepublic.com/focus/f-news/1026551/posts
Therein are contained all manner of topics such as: spread of disease and other health problems, higher levels of mental illness and drug and alcohol abuse, higher rates of child molestation and seduction, higher levels of being molested as children, the propaganda of the "gay" activists, how they indoctrinate children in schools, the wild promiscuity of the "gay" life, the undeniable fact that homosexuals can change, the causes of homosexuality (NOT proven to be genetic or inborn), and so on.
Read and learn!
All body organs have proper uses. The eyes are for seeing, the ears for hearing, the digestive system for digesting, and the reproductive system for reproducing.
The pleasurable nature of intercourse was designed to bring male and female together. All of this is simply a matter of observing the design of the plumbing.
But we can also know with certainty that intercourse was intended for married couples. How can we know this through unaided reason? Simply by observing the raising of children. Who today can argue that a child raised by a single mother is better off than a child raised by a mother and father? Surely the latter is what was intended by our Creator.
"Some people are just as naturally attracted to the same sex, as others are to the opposite."
No, sorry to contradict, but that's simply not so.
No one is "naturally" attracted to the same sex, nor ever has been, nor ever will be.
Everyone is intrinsically normal.
So called "attraction" to the same sex is a maladaptive response to molestation or seduction by a person of the same sex during a person's pre-adult years.
I refer to it as "so-called attraction" because it is not the same phenomenon as attraction of man for woman and vice versa, but merely a perverted and evil lust.
Same-sex attraction disorder is AFAIK the only contagious mental disorder. A sufferer can pass it on by traumatizing others. Not with 100% efficiency, of course. Not every molested boy develops the disorder, and sometimes it doesn't manifest for decades.
But that's how homosexuals "reproduce." The vampire legend, bitten becoming biter, is a metaphor for the way homosexuals create new homosexuals.
Trace any liberal position back far enough, and you will encounter an error of fact. Yours here is this notion that some people are "naturally" unnatural.