Did Jesus outright condemn homosexuality? As it has been observed by others, he didn't have to. He intensified all the commands against sexual sin.
A good analogy would be a Sheriff speaking to a classroom and telling the students, "Obey the speed limit when you are old enough to drive." He didn't specifically mention "The 40 mile per hour speed limit" because he didn't have too. Obviously it is included in "speed limits." Only a sophist would try to later make an exception for "40 miles per hour."
There are seven very clear passages in the Old and New Testaments that directly forbid homosexual practices. But it is often claimed that Jesus himself never addressed the issue. Proponents of gay lifestyles then use a supposed argument from silence on Jesus' part to justify, and even overturn clear New Testament teaching against homosexuality.
But did Jesus really never say anything about gay marriage or homosexual practices? And even if he didn't, would that in any way imply His approval of it?
What did Jesus say on sex and marriage? We have a number of statements that are very direct.
Talking about divorce, Jesus said, "...from the beginning it has not been this way. I say to you, whoever divorces his wife, except for immorality, and marries another woman commits adultery" (Matt. 19:9)
The word "immorality" (pornia) was a general term for any sexual misconduct. Thayers and Smith's Greek lexicon describes it as, "illicit sexual intercourse, adultery, fornication, homosexuality, lesbianism..." It is like the term "speed limits" in our opening analogy.
Jesus and his audience were ancient Jews. They had the Old Testament Scriptures and commands. That was their common background on these issues. All Hebrew boys were required to attend Hebrew school. The Torah (the law of Moses), the prophets, and the "writings" of the Old Testament informed their world view. It was these Scriptures Jesus made appeal to when He spoke of "the beginning," that is, the Genesis account of Adam and Eve, the first married couple, and the created order that God called "good" before sin entered the world in the Fall.
Given this context, and Jesus not making any hint that he was discarding the Scripture or modifying it, we must not discount what the Old Testament says about "immorality." All sexual misconduct were included in that term, including homosexuality, bestiality, and incest. In fact, in Matthew 19:8-10 if anything Jesus tightened up the laws and the standards on marriage, saying that the divorce certificate was not God's will or permission/blessing, but due to the hardness of man's heart.
And also in this passage three times Jesus or his disciples describes marriage as between a man and a woman. It is implied in His reference to "the beginning," as we said. It is explicit in v. 9, and his disciples spell it out in v. 10. If Jesus' intent were to overturn the prohibition on something this central to human life why remain silent? He in fact is explicit in the so-called "exception clause" for immorality being the one ground for divorcing someone. And when the disciples follow up with their comment about marriage, if Jesus' intent were to open up marriage to same-sex partners and overturn the Law why not take that occasion? His disciples knew the Old Testament law. Jesus knew that was their context and framework for morality. Silence clearly would be tacit support of the standard and in no way a door to something completely contrary to it.
Jesus didn't mention a lot of things. He didn't mention bestiality, which was also forbidden in the Law of Moses. Does that mean Jesus is in favor of it? Jesus didn't mention child abuse. Did He support it? Jesus didn't mention incest. Did He intend therefore to make it legal? By the logic of the gay rights movement, and ill informed statements of people such as former President Jimmy Carter, one would think Jesus favored all these things.
But Jesus was only three years in ministry. He didn't mention many specific practices as his focus was on the mission He was called to. Yet on many occasions He affirmed "the Law," quoted from it, appealed to it, and never excepted homosexuality or other such practices.
Quite the contrary, where there was a misunderstanding, or where on a few occasions a law was being superseded He explicitly taught on it. He corrected ideas about the Sabbath, he stated that all foods were now clean, and as in Matt. 19 he corrected false conclusions people drew from the Law. But never does He hint at softening what it says on sexual immorality as described in the Old Testament.
And we must not forget that John 1 teaches that Jesus was the creator! And he created Adam and Eve. Jesus was the Word, so, yes, He did speak very directly on gay marriage. The "helper suitable" for Adam was a woman, not another man.
Of course we must also look at the disciples of Jesus to understand Jesus' intent. These were the men closest to Him and taught by Him. And they are explicit on forbidding homosexual practice.