ero•ses•sion
N
1. A deeply intense preoccupation with a significant other in which one is drawn in completely to the growing feelings of love as a relationship progresses to stages of permanence as the mutual reciprocation of shared feelings, thoughts, desires, and attractions are merged into a healthy, fulfilling, and interactive relationship.
ero•ses'sion•al adj.
ero•ses'sion•al•ly adv.