Dealing with infidelity in marriage can cause other issues. The trust issues, as well as the pain, caused by the infidelity can often lead to neglectful behaviors, negativity driven by resentment, a decrease in sex, lack of respect, or the victimized partner may feel entitled to engage in new behaviors as a way to retaliate or show their disdain. Communication is often affected, one or both parties may cease to talk, or they communicate negatively or differently than they used to, prior to the incident. Also, when one partner is always suspiciousm of the other, arguments can easily ensue. A person victimized by infidelity really needs to consider whether they want to work on the relationship to stay with their partner, and must be willing to forgive to do that. The ways that marital problems can escalate is the reason counseling is so important in order to effectively cope after infidelity has occurred.
Trust issues will obviously follow infedelity. It can take years to rebuild this trust, and it is hard to have a healthy marriage when this trust has been broken. How can you build a life with someone that you don't trust? How can you give your heart to someone you don't trust. Infedility can cause a whole host of other issues.