Actually no. No one is "pulling out the Old Testament" and the announcing that the "Old Testament no longer applies". You show your ignorance of Christianity.
Jesus seldom referred to the "laws" of the Old Testament because during his time, the Old Testament was the Law of the land. It would be like someone reminding you constantly that speeding is wrong. No joke.
Therefore, everyone knew that homosexuality was wrong in the sight of God. Nothing new there. Unlike gays today who pervert the word of God to fit their desires. Nothing new there, people have misinterpreted the Word of God (for their benefit) for centuries.
The only REAL time that Jesus absolutely backed up his "stand on marriage" was when confronted by the Pharisees, who had set out to "trick" him into saying the wrong thing:
"And Pharisees came up to Him and tested Him by asking, “Is it lawful to divorce one’s wife for any cause?” He answered, “Have you not read that He Who created them from the beginning made them male and female, and said,
‘Therefore a man shall leave his father and his mother and hold fast to his wife, and the two shall become one flesh’? So they are no longer two but one flesh. What therefore God has joined together, let not man separate.” They said to Him, Matthew 19; 3-7
So, gays can attempt to justify their behavior in any way they choose. That's their business. Biblically, they don't have a "leg to stand on". But then, they really don't care - now do they?