Excessive possessiveness can destroy a relationship.
Tips
usage
Often paired with a quantifying adjective: 占有欲强 (strong possessiveness) is the most common collocation, especially in relationship discussions. Related: 控制欲 (desire to control) and 表现欲 (desire to show off).
memory
占有 ('to possess/occupy') + 欲 ('desire'). The suffix 欲 is highly productive - attach it to nearly any verb to get 'the desire to X.'