[mfisher87]

That's not what he's arguing. I don't think anyone's arguing that any penises have evolved some features that make them more lickable.

These are claims that non-procreative sexual behaviors have naturally evolved. A counter-argument to the idea that the only natural sexual use of the genitals is penis-in-vagina-sex. Claiming anal sex is unnatural because you can't produce babies is the same as claiming that masturbation or oral sex are unnatural because they can't produce babies. Seeking pleasure is NATURAL, evolved behavior. I don't think you're genuinely reading people's claims carefully.