I am sorry but Bukharis hadith is considered right after Quran and many aspects of Sharia are derived from that. From what Mohammad did himself. There are tons of Islamic scholars who agree to this.
Just because you decide its not applicable in Sharia does not mean it will be so. This is there, it is a fact. And it is inexcusable.
So pre marital sex is prostitution? Only an Islamist can come up with such logic.
I am an adult, over the age of 18. I can make my own choice as can other people.
If two adults consensually decide to have sex, the State is no one to intervene. This is called individual rights.