I don't know if it's a preference or innate. Nor do I care.
Gays are sinners. But so am I. So are you. So is everybody. I don't hate anyone because they sin differently than I do.
I support gay marriage (more on that in a moment), but the thought of gay sex repulses me. But some forms of straight sex repulse me, too. I'll stay out of everyone else's bedrooms if they stay out of mine. Deal?
Supporting gay marriage is, I believe, a very conservative position, and also a Christian one. Let me explain.
You can't legislate morality. Sins committed in the heart are just as hurtful in God's eyes as sins committed physically. A thief who steals is just as sinful as a thief who WANTS to steal but doesn't. In places where gay marriage is illegal, there are still gays. A lack of marriage is not preventing anyone from being gay. Nor will legalizing gay marriage cause more people to be gay.
Gays are here to stay. They're not going anywhere. There's no reason they should not be granted the same rights as straights.
Of course, the ultimate conservative position is to get government out of the marriage business altogether. But that's not likely to happen.