To screw up your marriage in an exceptionally effective way, let your eyes wander and make sure your partner knows it. An important part of a stable marriage is that both partners feel secure in the relationship and that they can trust their partner. If you want to screw up your marriage, chip away at that security until your partner has no choice but to doubt your fidelity.
There are a few ways to do this. Talk openly about your attractive friends and coworkers to your partner so they can be absolutely sure that you find those people attractive. Better yet, offer these thoughts completely unsolicited, especially if your partner says they don’t want to hear it. Leave your partner wondering why you are looking elsewhere and what those other people have that they don’t. Similarly, talk openly about how your partner is not your traditional type. Let your partner know that other people are on your mind by frequently calling them by the wrong name, especially in intimate situations.
To make your mind wander and eyes look elsewhere even more, put yourself in situations that might tempt you. Reach out to your ex to discuss some recent issues you’ve been having in your marriage. Go to happy hour with the coworker you find attractive instead of coming home to eat dinner with your partner. Maybe most important, if you find your mind starting to wander, keep it to yourself and don’t talk to your partner. This will likely increase the chance of you acting on impulse while giving your partner none of the validation of their suspicious being correct. If there is a specific aspect of your relationship that is causing your mind to wander, don’t address it. Keep your in the dark while allowing all light in your marriage to be extinguished.