A true "revenge" adultery couldn't be a "hall pass" version of the thing, incidentally, as far as I'm concerned.
Sex with consent is called "making love" or "casual/recreational sex" or else it's a kind of barter or payment/reimbusement/reward for something the participants gave or want in return. Or it's a power play or manipulation of some kind. Or it's prostitution.
Sex WITHOUT consent is rape. Or molestation. Or theft. Or adultery (from the BS's perspective).
The difference largely lies in the control and allowance or lack thereof in the situation.
Another difference lies in the valuing of the thing and the relationship and the integrity of BOTH, as well as one's own personal sense of integrity and values.
If I think the world of my wife and her sexual purity, but SHE doesn't feel the same about ME and mine or even about her own "purity" or the purity of a monogamous marriage, then it's a very different thing for me to "lose" her and my vested part in all of those things than it is for HER to "lose" something and someone that she's already counted as lost to her, or counted as not worth keeping sacred and consequently gave away for freaking FREE to people who didn't even value her one freaking BIT.
That's like telling a 4-year-old toddler that you'll give them a nice, yummy Jolly Rancher or a candy sucker-ring or some bubble gum in exchange for the tasteless diamond/gold-metal ring his mommy or daddy takes off and leaves by sink while they're doing the dishes every night. It's just not apples-to-apples.
To be an even exchange, it seems to ME that the WW would have to somehow value the spouse and/or marriage and fidelity and trust within that relationship to be intact and held in just as high an esteem as the BS did BEFORE the first-blood act of adultery was ever committed in the first place.
Then, after THAT, it would have to be done very much AGAINST the WW's will and "persmission" and sense of control. In fact, I think that a very great deal of the adultery thing that WW's engage in often has a LOT to do with simply exercising some kind of control in their own terms and conditions...and I think, too, that it is sometimes done as a way of not only exercising control for themselves, but also of TAKING control AWAY from their BS in a very REAL way!
I'm not recommending a plan of action for revenge here, btw. I'm only saying that my own wife gave me such a "hall pass" herself, but that's not the same thing as feeling raped and left for dead and stuck with keeping my own vows with her and God like I feel that I was.
I can't see that I would EVER give her such a hall pass of that nature, even if I were to be a WS, because I value sex and marriage and my wife and my vows and my faith and my God and my own integrity and even my own self-respect and self-esteem, and I even respect for OTHER WOMEN and THEIR bodies--ALL of these things and concepts--soooooooo much MORE than she did at the time!
Hell, I even respected HER and HER body and HER sexuality and purity better than SHE DID when we were actually just friends as WELL as when we both were courting/betrothed to be married! I say this because it was ME who set the boundaries for the both of us and kept holding things back, sexually speaking! And I'm the GUY for crying out loud!
I not only tried to look out for her honor when we were just talking about her boyfriend she had when we met at church summer camp hundreds of miles away from our respective homes, I also counseled her to watch her own gestures and signals/vibes she had while she was with ME and others, and she hadn't even had sex with me or anyone ELSE at that point (and neither had I, for that matter).
But I guess talking about all of this does help me to even better see how I feel about RA's once I get it out "on paper" some. I appreciate the questions and the topic being posed and so well remarked upon, even if it wasn't "my" topic to begin with.