Humans have the most brutal male domination system in all of nature. Females throughout the animal kingdom choose males for their resources. Female choice may have played a key role in the evolution of some males' genitals. Some females can choose males for their good genes. Traditionally, love goes with adultery, not marriage.
Human beings are a mildly polygynous species.
For most of the world, love has nothing to do with marriage. Women and men pursue different sexual strategies. Men and women have different sexual fantasies. Some males go to any expense to subvert female choice, even infanticide .