Before you worry about revenge (which you might want to reconsider anyway — revenge is almost never a good idea), worry about getting your own house in order. If you’re in a long-term relationship — or even married to — someone who has just been caught cheating on you, there are some things you want to do.
1. Stay Calm
Above all, try to stay calm and don’t do anything you’ll regret later. Emotions run high, and you want to take the upper ground. You are in the right here. Even if you have been hurt, you can still abuse your right until you’ve turned it into a wrong. You can be cold, distant and withdrawn from your cheating partner — but do not get angry, start yelling or get physical.
It’s wrong, first of all, and second of all… it can only hurt you worse in the end. Is it worth going to jail for your cheating partner? Don’t hurt or threaten them, don’t destroy their stuff, don’t do anything other than act like a calm, collected human.
A.1 Sexually Transmitted Infections
GET TESTED! Make sure you’re healthy. Your partner has not been honest with you about many things, so unfortunately, an unfaithful significant other could potentially damage your health. If cost is a concern, you can go to Planned Parenthood or a similar low-cost clinic. Get tested ASAP. Do not wait. If you did get an STI, getting treatment early could save your fertility and prevent numerous complications.
B.2 Personal Safety
If you have to confront your partner and think there is even the slightest chance of your partner retaliating physically, do not confront your partner alone. Have at least two friends with you if you decide to confront them (make sure your friends are the calm and collected type, too — no need for hotheads). This goes for everyone. Your partner might decide to attack you, or they might call the police and report a domestic incident. Having witnesses to provide your side of the story can go a long way.
Change the passwords for your e-mail, cell phone account, bank accounts and anything else that’s in your name that your partner could have had access to. Make a list of all your passwords: focus on the important stuff like cell phone and bank account first, but don’t forget Facebook and Instagram either — you don’t want a spurned ex sending porn to your boss via your Facebook, after all. That’s a seriously awkward conversation at best. Never, ever forget to change the Netflix password.
If your partner has tried to gain access to your personal accouts or information before, you’ll have to take it a step further. Turn on “two factor authentication” on your important accounts — you’ll get a verification text anytime you try to sign in on those accounts. You can also contact your bank and other places where you have an account and ask them to make a note that someone may try to compromise your account. Your ex has a lot of your personal information; if they decide to be vindictive in this way, you’ll want to be prepared.
Pack up anything valuable or sentimental and find somewhere to store it. Do so on the sly, if you haven’t confronted your partner and you don’t plan to do so. You don’t want your partner asking why you’re moving twelve boxes out of the apartment, after all. But if you can sneak a couple sentimentally valued items out, do it! People can be vindictive and anything you don’t want destroyed, make sure it’s safe.
That said… make sure you’re taking YOUR items, not their items or any valuable shared items. This is especially the case if you’re married and your assets are highly co-mingled. There will be a time to sort out who owns what later. Taking something that’s not yours (even unintentionally) can make your life harder later on.
5. Let It Go
Don’t start rumors. Don’t start drama. When the cheater inevitably gets a new beau, don’t approach that person and inform them of their partner’s past cheating habits. Don’t blow up Facebook or spew your personal business across Twitter. First of all, it doesn’t look good to anyone aside from vindictive, petty individuals. Second, you’re only prolonging your own hurt. The sooner you can move forward and move past this, the sooner you’ll feel better.
The obvious exception is when the cheater shacks up with a close friend or someone you care about. In these situations you can approach with care, but do realize not everyone will want your help. Many people believe it’ll be different for them with someone who cheated in the past — and sometimes, sure, it can work like that. Often not, though — so make sure you’re available with a shoulder to cry on later if you want to keep the friendship open!
The worst thing you can do is take some kind of vengeance on your partner. Destroying their stuff can cost you big-time when you’re held civilly liable in court later on. It’s not worth it. Is your cheating partner worth going to jail or paying fines? Do you want to get taken to court and have to pay them a bunch of money for stuff you destroyed?
6. Stay Un-involved
Right after you learn someone has cheated, it’s pretty easy to walk away. You’re hurt and angry. But as time passes, you might be tempted toward forgiveness, or even getting back together. If you chose to leave someone over their infidelity, you need to stick with your decision for a while. Make sure you really want to go back before you go back. It can be really hard to separate yourself from someone you loved… but it might be for your own good in the long run. If, after some time of separation, you really feel it’s for the best to get back with your partner, you can do it. Just make sure it’s really what you want and not a decision made with cloudy judgment. Only you know what’s best for you, so it’s important to make sure you’re making your decision with a clear head.
7. Bonus Marriage Tip
Save your evidence before you confront your partner. Take pictures of receipts for dinners you think they had with their side-piece. Get copies of the phone bills and credit cards, if you have access to that material normally. Take pictures of your shared living space, your valuables, etc. Again you are legally entangled with this person now, and unfortunately divorces can be very messy. Make sure you cover your own bases — your partner will not!
Remember: if you’re married, you have made a legal obligation to your partner. No matter what they have done, you still have that legal obligation until you are divorced by a court of law. Be very, very careful about locking someone out of co-mingled assets. It rarely looks good, and can even open you up to further trouble (it won’t look good to the divorce judge, and it might even be illegal in some cases). If you’re married, the rules are totally different — and you could get in serious trouble for draining joint bank accounts, preventing access to a home, and similar. If you’re married and you discover your partner has cheated, lawyer up immediately if you want to end the relationship. No one can advise you better than a lawyer.