Only eat oysters in months without an 'r'?

No, silly, it's only in months with an ɹ.

Not sure about where you're from, but aren't most oysters flown in from the northern hemisphere?

Bluff oysters, coffin bay oysters, sydney rock oysters, tasmanian oysters, etc, etc. And that's just some of the 'local' ones.

Never heard of an oyster flown in from the Northern hemisphere. Pacific oysters (from Japan) are cultivated in Coffin Bay and Tasmania. Native oysters predominate in most of NSW, where Pacific oysters are classed as a noxious species.

I never touch Pacific oysters in the later summer months - mainly because spawning makes them taste awful. Sydney rock oysters are great in the summer fortunately.

There's plenty of home-grown oysters in Australia.

Yeah, but they're all trying to kill you.