"What about your view of sexuality?"
I get my daily news updates from Albert Mohler's The Briefing and if a story warrants further reading, I'll seek out the sources. But what I rarely get updates on are popular entertainment stories like the one where former President George Bush and Ellen Degeneres sat at an NFL football game together. Apparently, this caused a lot of controversy, because he's a known conservative (a professing evangelical to boot) and she's gay.
Nothing has become more complicated and controversial than sexuality in our culture, but historically Christian sexual ethics have always been countercultural, so there's nothing new there.
But among you there must not be even a hint of sexual immorality, or of any kind of impurity, or of greed, because these are improper for God’s holy people.
What is new is how complex sexuality has become -- pansexual, bisexual, transexual, transgender, asexual and those don't even skim the surface of a vastly evolving list. This means at some point as a Christian you are probably going to be confronted for your old-fashioned binary view of sexuality.
Now, there are good defensive arguments, such as males have one Y chromosome and one X chromosome, while females have two X chromosomes, so no one with a Y chromosome will ever have a baby. It's a scientific impossibility, which tells us something true about sexuality.
However, rather than go on the defensive, keep it simple. Frame the discussion this way with a person who supports the worldview of the sexual revolution: "You believe your view of sexuality is right. Why?"
That's it. Everyone believes their sexual ethic is right. But based on what?
The moral argument for any behavior is always, "Says who?" If there is a personal God, then He is the definer of reality, not humanity.
It comes down to the sources of moral authority in a person's life. For most people, these sources are not transcendent and therefore any claims for universal moral authority are lost. This just means it's hard for them to argue for absolute morality. And if someone who supports the sexual revolution doesn't have an absolute morality to argue then it's unreasonable for him or her to become upset when a Christian doesn't happen to agree with his or her view of sexuality.
Then simply stress this doesn't mean you're narrow minded. It means you have a different worldview than your friend, relative or coworker who supports the worldview of the sexual revolution .
The difference is the Christian's sexual ethic has a basis that originates outside of himself or herself.