Administered questionnaires to 140 couples to test the hypotheses that (a) feelings of love become more highly correlated with trust and acceptance as relationships develop through time and (b) parental interference in a love relationship intensifies the feelings of romantic love between members of the couple. The 1st hypothesis was derived from the authors' conceptualization of love and distinctions between romantic and "conjugal" love. Affirmation of this hypothesis was found, supporting a methodology for operationalizing romantic love. The 2nd hypothesis was derived from classical literature and small group dynamics, and was explained in terms of the motivating effect of frustration and reactance. This hypothesis was also supported, using both cross-sectional and longitudinal change score correlations. Possible relationship dynamics associated with parental interference and trust are discussed. Findings are applied to cross-cultural variations in the occurrence of romantic love. (15 ref.) (PsycINFO Database Record (c) 2016 APA, all rights reserved)