I hope the good Christians who oppose homosexuality based on the Bible also support slavery.
Gotta be consistent.
to be fair most Christians who cite the Bible as a justification for opposition to homosexuality do so based on the Pauline letters and not based on the Law of Moses, which expired (or "was fulfilled") when Christ was crucified (and contains all sorts of things patently absurd to our contemporary sensibilities). the NT is much more nuanced on the issue of slavery on the occasions when it comes up at all.
Hmm...I disagree. They most often use Leviticus because it is most blunt about the subject. They don't realize that the same code outlaws certain blends of clothing, outlaws shellfish, and says other stuff that we find unapplicable, which is because it is an old Jewish code of law and not intended to be used as our law.