What does the phrase "anything goes" mean?

It's just a cute, quick way of saying people are open to adventure, romance, anything. The phrase is a little suggestive, a little , but still genteel, especially as Cole Porter used it. Truth is, almost nobody would actually mean that phrase literally, except really drunk people who would then probably end up dead after playing Russian roulette or walking the white line on a highway. For most people, most of the time, the phrase is just an indicator of openness.