Understanding each other's pet peeves is crucial for a harmonious relationship. Common pet peeves in relationships might include poor communication, lack of punctuality, messiness, interrupting while speaking, or neglecting shared responsibilities. However, pet peeves are highly individual and can range from minor annoyances to significant issues. It's important to communicate your pet peeves respectfully to your partner, explaining why certain behaviors bother you. Remember, the goal is not to change your partner entirely, but to foster mutual understanding and respect.