mate poaching
behavior that is intended to sexually attract someone who is involved in a committed romantic relationship with another partner. In evolutionary theorizing, mate poaching is one of several evolved adaptations, or strategies, for increasing or improving one’s reproductive opportunities. Partners in committed romantic relationships often engage in mate guarding to thwart the possibility of mate poaching. Research shows that mate-poaching attempts are commonplace in most cultures in the world. Among nonhuman animals, sneak mating is a somewhat similar behavior in some males.