Earlier quoted context omitted.
> "Selling is legal, and fucking is legal; but selling fucking is not legal." I don't get it. The literal interpretation is a clear joke, as you say. So what's the point that it is making? To be clear, I think the law discussed is stupid. I also think the argument that if both parts are legal they should also be legal together is wrong. What am I avoiding?
I'm referring to the two other jokes you quoted.
What was I avoiding with those?