Can you? Is this possible? Many writers present plans that are supposed to be near fool-proof. Some are aimed at husbands; some are aimed at wives. Do this, be that way, and you can prevent your partner from straying. It’s appealing, and, on the whole, good advice about how to make a marriage more secure.
However, I think the only way to truly affair-proof a marriage has to do with something both partners commit to doing together. The agreement can be tailored to your relationship but should include things like prioritizing the marriage above all else, maintaining emotional openness and transparency including a commitment to disclose attractions to others.
Unfortunately, most couples enter these kinds of agreements only after there has been an affair, when the costs of not having done so have been brought home in the most devastating way possible. Without this hard lesson, it is easy to assume that your partner’s ideas about boundaries are the same as yours and that you do not need an explicit agreement addressing relationships with others. It is also easy to assume that this should happen naturally and not be difficult to adhere to.
But it probably will be difficult, not all of the time of course, but at times. Being married does not eliminate attractions to others. It’s tempting to believe it does; this is an idealized version of marriage. The more emotionally alive you are, the more connected to others you will feel. Although jarring at first, accepting this reality together can eventually strengthen your marriage and set the stage for disclosing attractions to others in the future. Affair proofing your marriage means an attraction to someone outside the marriage acts as a signal to share these feelings with your spouse.
If both partners stay committed to the plan, the likelihood of an affair is extremely small. But the plan only works as long as both partners keep working it. This kind of openness can fly in the face of your instinct to protect your partner from anything painful. If the two want this kind of commitment, but are having trouble making or keeping the agreements, Marriage counseling can be very helpful.