The paper discusses the development of moral theology in the Roman Catholic Church, the way this development opened the doors to the various methods and schools of thought, philosophical and theological worldviews, the ways of perceiving and comprehending human experiences theologically, and of grasping the depths of personhood and a personal being. One of the greatest options for overcoming the reductionistic tendencies in manualist tradition in moral theology was relational ontology. The latter was the theological grounding of the dynamic trinitarian ontology. This paper explicates the influence of dynamic trinitarian ontology on moral theology and precisely on sexual moral theology.