Part 1. Definition
In this task, you are given a public comment from online platforms. You are expected to classify the comment into two classes: obscene and non-obscene. A comment is obscene if it is considered offensive to the public sense of decency, for example because it too obviously relates to sex or contains language regarded as taboo in polite usage.
Part 2. Example
Comment: Damn! Another cloudy day, and it's all Obama's doing!
Answer: Obscene
Explanation: This is obscenity because it hints on sexual content that is offensive to the public sense of decency.
Part 3. Exercise
Comment: There is no issue to avoid. Were it not for the fact that there is vociferous LBGT lobby in the West, there would be no discussion at all.

I've been through this exact drill for decades. The rabbis were wrong, the early Church wrong, everyone got it wrong until really really smart people found the mistake. Thus your cohort's ""there is no such think as 'the' natural law".

In reality the moral content of the Old Testament carried over into the NT except where specifically corrected, e.g., Mark 6-12. This included prohibitions against murder, incest, fornication, bestiality, homosexual relations, and so on. The Natural Law, which the rabbis identified but used other terminology in describing, remained intact.

Because the Church's teaching rests on two pillars - Scripture and Tradition - that "Jesus ... never spoke of it" is irrelevant.

Jesus' audience was Jews, and they did not need to be instructed that marriage consisted of one man and one woman.
Answer:
Non-obscene