Truly, the sex rating depends on how you want to interpret that pesky snake. If you see it just a straight-up stand-in for a male body part, then we can see how things can quickly get risqué. Notice how this “narrow Fellow” isn’t ever called a snake. Let’s see… He rides along. He combs the grass. And hello… he’s described as a shaft going through an opening in the grass between the speaker’s feet!? If that wasn’t enough, this snake leaves the speaker in ecstasy (a.k.a. “transport”) and short of breath! Why Miss Dickinson, we had no idea!
Of course, that's just one possible interpretation. If the snake seems less a phallus and more about the blurred line between man and nature, or between perception and reality, then bring the kids, gang! This would get a big, family-friendly G.