Jesus never spoke on the issue of gay marriage. That’s what my LGBT friends report. If we’re looking for those specific words, then they are correct. But on the other hand, there are other issues, such as embezzlement, of which Jesus never talked about either. However we know His teaching on the specific because of what he said in the general about possessions. “Give to Caesar what belongs to Caesar and to God what belongs to God” and other references. In like manner we can see that Jesus covered not only the idea of gay marriage, but all marital issues when He took the religious debaters of His day all the way back to Genesis.
God created mankind distinctly as male and female. The two being differently and completely complimentary to each other. The essence of the act of marriage is the union of those two different beings into one.