I always explain that Leviticus should not be in the Bible and that they got Sodom and Gomorrah wrong. Matthew 15:10 and Genesis 9:3 vs. Leviticus 11. Sodom and Gomorrah was about having unloving hearts, not about being gay. It is also very ironic that they are so upset with gay marriage but not with adultary which is one of the Ten Commandments, an actual commandment. They also don't care about the two Great Commandments that Jesus gave or anything else that He taught. Yet, despite the fact that they don't follow Jesus, they believe that they are Christians.
What is really happening is Matthew 24:12, 2 Timothy 4:3 2 and Timothy 3:1-9. This is evil in action.
Hold fast to these. Luke 16:14-15 and Matthew 7:22-23 because 1 Corinthians 13.
To God, it is all about the heart. God bless you, my sister in Christ.