Let's just say hypothetically I was willing to concede the "Conservative" argument that our Biology proves God clearly designed us for inter-sex relations exclusively and there for that's the only intent.
Is there any other thing where we consider it a Sin, or an abuse, or even disrespectful to use something for something or anything other then it's created purpose?
We proponents of Intelligent Design keep using the analogy of a Human Designer designing artificial inventions. I can list endless examples of people commonly using an invention or a created object for something other then it's original created purpose. We use newspapers to discipline dogs, tins cans for target practice, anything with a significant density as a paper weight.
But people aren't like God, so let's look at how humans use what God gave us.
Our hands are what were deigned to hold things, but if their full we'll also use out chins or mouths.
That analogy might seem silly to you. But to people who aren't conditioned to be grossed out by it calling Homosexual affection unnatural is silly.
God clearly did not originally create Animals to be food for Humans, in fact it was a Sin for us to eat them Pre-Flood. But that was changed after The Flood.
And was the created purpose of Trees to be cut down for humans to make various artificial objects out of them?
So that makes it clear to me God is capable of accepting flexibility in how we use what he created. As long as we're not breaking The Golden Rule, or worshiping a false god.