If Jesus did not in fact say that, it doesn't mean that Paul and Christ are in contradiction with one another. Not saying something does not mean acceptance or approval.

That said, Jesus has made a stand and voiced opposition against homosexuality. 

First, Jesus is God:John 8:58 - Jesus said to them, “Truly, truly, I say to you, before Abraham was, I am.”

Second, Jesus existed before the earth began: John 1:3 - All things were made through him, and without him was not any thing made that was made.

Third, God said from the beginning that it stands against his law: Gen 19:4-11, Lev 18:22.

Fourth, Jesus entered the world not to abolish the law but to fulfill it: Matthew 5:17.

Fifth, Paul and the other apostles being filled with the Holy Spirit of Truth would not preach a different gospel than their Messiah.