Acadia,

What someone finds erotic/arousing is (fairly obviously) subjective.

Erotic: "Pertaining to sexual love, amatory, amorous" (Chambers Dictionary).
Which leaves a plethora of options open, no?

You (or I, for that matter) could create a picture which to your (or my) mind was sexually innocent. But others might not view it that way...

There's no "black/white" rules (or even guide-lines).

Which is why I don't post in the galleries here...:-))

Cheers,
Diolma