What are some specific ways that you go about preventing the bond between your spouse and the OM / OW from growing stronger?
Guilt is good, that's why the feeling exists, it's a personal barometer which tells you that you may not be doing something that is good.
Obviously don't condone this behavior, setup boundaries and limit your contact with your partner if they refuse to stop.
You have to draw a line that can't be crossed, if they are willing to cross that line and have an affair with someone else, they've lost your respect and need to know that you aren't going to be there waiting with open arms when they return to their senses - they are actively hurting you, it's not a good thing.
Don't know what else to say, it's definitely a crap situation to be in, I wish you all the best with this.
Make sure you take care of yourself during all of this, don't let what they're doing hurt you and cause you to go into depression.
