Communication is the key to any successful relationship. Being able to speak openly with your partner about anything is important and being able to bring up uncomfortable topics, like infidelity, is of the utmost importance. Discussing the hard topics is difficult for both partners involved but needs to be done relatively soon in a relationship. Waiting until marriage to discuss what you each consider cheating will not do any good. This will leave room for one of you to cross a line that you didn't know existed. Being open and honest from the start will help keep your relationship on the right track to stay happy and healthy.
There are many reasons that people cheat so make sure that not knowing each other's boundaries isn't one of them. Setting clear boundaries is extremely important early on in a relationship so that you know your partner's expectations and they know yours. You have to know what your partner considers cheating and what, if anything, you disagree on. Your partner may consider you having drinks with your ex as cheating, while you encourage your partner to have a friendship with their ex. These distinctions are important for each partner involved to understand and respect. Many people may think that cheating is entirely physical, however; it is possible to cheat on your partner without touching anyone. Emotional cheating is sometimes considered worse than having a sexual encounter with someone because of that connection that you share. Your partner wants to be the only person that you feel a truly deep, emotional connection to. Some partners may feel more betrayed by you having an emotional attachment to someone then you having a physical encounter with a stranger. Setting boundaries will help prevent misunderstandings when it comes to infidelity, among other things.
If you've passed this point in your relationship and a boundary has already been crossed it does not mean the relationship is over. Boundaries are important to set whenever you and your partner decide to talk about it. If someone has already crossed a line or you just want to take preventative measures, it is best to seek advice from a licensed therapist. Therapy is not just for people struggling to keep their relationships together. It is also good for maintenance. We see a doctor for everything else. Getting a checkup on the health of your relationship is just as important as a physical that you get.
Be honest with yourself and your partner about your expectations in your relationship. Help to prevent infidelity in your relationship by having open discussions, setting boundaries, and consulting with a professional to maintain the health of your relationship.