[DJHenk]

> What is this article about?

It is not an article, it is an essay. Wikipedia defines an "informal essay" as: characterized by "the personal element (self-revelation, individual tastes and experiences, confidential manner), humor, graceful style, rambling structure, unconventionality or novelty of theme," etc.

> What did the sex part of it actually involve?

The reason that this part is left to the imagination of the reader is that A) it is more powerful that way and B) the details don't really matter anyway to get the message and image across.

These things should have been covered in your creative writing class too.