This document provides methods for monitoring a partner's activities to check for potential infidelity. It discusses observing changes in their behavior, monitoring their online history, emails and texts. It also describes using spyware, keyloggers or GPS on their devices, hiring a private investigator, and confronting them while suggesting counseling. However, it warns that spying could be illegal and damage trust in the relationship. It's best to communicate openly with your partner rather than spying.