The principle is about ensuring that the truth and facts are revealed.
In most cases during infidelity the wayward spouse will spin a line of stories about why they have movedo out, why the marriage isn't working, and why they have filed divorce etc...
They will either lie to everyone that the OW or OM is "just a friend" or they will lie about the marriage being "a mistake" and that they are "moving on"
At the same time in secret they are conducting a sexual affair, or they are cake-eating and leading their LBS on in private...
In some cases the WS is even arrogant enough to lie to their family that the LBS APPROVES of the affair and that they are both "moving on" when the LBS in fact does NOT approve and is NOT "moving on" and very much wants the marriage saved.
The purpose of exposure is to ensure that the TRUTH and the FACTS are readily available to everyone and that the addicted WS is NOT spinning lies and getting away with it.
The exposure on your end should make the following points known :
a. Infidelity is hurtful and you feel devastated b. You want to save your marriage c. OW is an interloper and obstacle to the marriage being saved d. Invite them to refuse to participate in WH's affair by refusing to meet or socialize with either of them until he ends his affair
If you stand by these points, then make them KNOWN to your social circle and RE-EXPOSE any lies your WH is spinning about to people...
This is not to be "vendictive" or "mean"... if anything it is an expression of how much you love your spouse to speak up in public like this and to protect your marriage, your home, and everything you have worked for