Ask CriticalThought, he seems to have some secret argument for legalizing gay behavior, when the other five corruptions remain illegal, that he refuses to reveal.
And yes, "consent" is a large part. Gays argue "consenting adults," with "no victim," as a justification for legalizing gay behavior. If prostitution is also "consenting adults," with "no victim," then this argument holds no weight. How can one say to the gay, "OK, there's no victim, so your behavior is now deemed legal," without also saying the same to the prostitute or the polygamist or incest? If there are other valid arguments against the other three to five corruptions, please enumerate them, so they may be dismantled as well. The similarities are clear for all to see. Merely citing consent doesn't persuade society to legalize prostitution (polygamy or incest) and it therefore, can't justify gay behavior.
Prostitution is a sex act that society has deemed slightly illegal. Libertarian's often argue "consenting adults," "free country," and "no victim," but they haven't been persuasive. The similarity to gay behavior is inescapable. This one example should be plenty to convince the reader. Nevertheless, there are polygamy and incest which are also similarly consensual, "free country," and "no victim," but remain illegal. Any one of the three are more than sufficient to discredit gay claims based on this principle.
Again, if there are other principles gays would like to assert, please present them so we may dismantle them, as well.