If a person commits a "sin," it is nobody else's business. According to the Christian narrative, an individual has to account to the Supreme Being only. It makes no sense to emphasize or criticize one "sin" over another, and certainly not in matters of civil public policy. This entire anti-LGBT thing is a hoax brought to us all by people who seek to abuse religion to justify their own sexual insecurities at someone else's expense.
An individual who has sex before he or she is married, or with someone other than his or her spouse, or divorces and marries another while the first spouse is still alive will, according to the Christian narrative, be judged in the afterlife, as will people who commit "sins" that have nothing to do with sex.
BTW: Wow. I didn't realize that Ratzinger (Benedict) and Timmy Dolan, the American Council of Bishops, and their ilk were "liberals." I'm glad I got out of the RC Church when I did so long ago, and before I learned what the RC hierarchy did during WWII and the disgraceful treatment of women in Ireland and elsewhere.