Events or behavioral patterns that cause uncertainty in a relationship are called uncertainty events. They may be caused by competing relationships (romantic or platonic), deception or betrayal of confidence, fluctuations in closeness, and sudden or unexplained changes in sexual behavior, personality, or values (Planalp & Honeycutt, 1985). One or both partners are left wondering about the cause of the events and their significance for the relationship. If your romantic partner suddenly starts withholding information from you or a close friend begins engaging in activities that you find offensive, you will experience uncertainty. Uncertainty events may be sudden and very noticeable (betrayal of confidence, for example), or they may be subtle and escape immediate attention (your sister gradually stops returning your phone calls).