Reminds me of the teenage fantasy of being a little fish, and swimming up into -- not the anus, actually -- of the beautiful lady and setting out on a journey of exploration up into her body, from the inside . . . .
The first really good underwater photographs I ever took (had them published in a rather prestigious magazine) were of a five-toothed sea cucumber. But if you fuck one, don't go anal, because that's where its teeth are. Kind of ass-backwards.