I think the CARM staff writers answer it pretty well. They make a distinction between moral truth and emotions. Here's what they wrote: "Whether or not a homosexual couple is committed to each other is irrelevant to the argument since love and feelings do not change moral truths. If a couple, not married to each other but married to someone else, commits adultery yet they are committed to loving each other, their sin is not excused.
If homosexuality is made acceptable because the homosexual couple "loves" each other and are committed to each other, and by that logic we can say that couples of the same sex or even of different sexes who love each other and are committed to each other in a relationship automatically make that relationship morally correct. The problem is that love is used as an excuse to violate scripture. Second, it would mean that such things as pedophilia would be acceptable if the "couple" had a loving and committed relationship to each other. Third, the subjectivity of what it means to "love" and the "committed" to another person can be used to justify almost any sort of behavior."
Practically, I would say - again - we must counter a point in love. We cannot blurt out these objections with a self-righteous attitude. We must - by God's Spirit - remain humble as we speak the truth logically and clearly.
[Answered by Pastor HM]