I think she had sex with her best friend's husband, and finds it to be exciting. Then she came on here to share her tale, and see how worked up we'd all get about the raunchy story that she claimed was her "friend" and was "hypothetical." I think she finds it all to be very exciting to her otherwise mundane life. She wanted to tell SOMEONE what she did, even though she tried pathetically to disguise it as someone else's story. She knows she can't tell anyone IRL.

And there is my theory.