The issue here seems to be about how far we should trust our perceptions when those views conflict with the world view that we believe. The problem here is that the New Testament is full of warnings about the fact that as Christians we are liable to be deceived. And of course part of the problem is that a simplistic application of theology is likely to come up with the wrong answer.

In the case in your assumption that I'm saying that 'what they think passes for love between themselves is valueless and wicked and they are just lustfully kidding themselves'. This is obviously fallacious, and if I was trying to defend that, of course I deserve your challenge. However my view is far more nuanced. My understanding is that the world is built on the basis of a number of spiritual principles that can't be avoided; they will have effect. A good example of this 'You will reap what you sow' - and this works both ways: if we 'sow' good things, then we get good stuff, whilst if we sow negatively, then we will get bad stuff in return. In the context of a gay relationship, the fact that both the partners are sowing their love and commitment will result in a positive outcome. But that doesn't prove that it is blessed by God. By contrast at the core of the Christian gospel is the claim that 'without faith it is impossible to please God' and 'by grace you are saved'.

One of the best concepts that came from the 'Yes Minister' series on BBC-TV was the irregular verb and we have an example here:

I always assess every new situation fairly
You are somewhat fixed in your ideas
He is a rabid fundamentalist.

The truth again is far more complex; we all have basic principles on which we judge a new situation; the only question is whether those principles are Godly and coherent. I am following my principles - and you are following yours. Unfortunately we come to opposing conclusions.