You've likely encountered serial monogamists (or are one yourself). They prefer long-term partnerships and leap from one to the next.
Monogamy affects this sign differently. "Leos are incredibly loyal and would never betray on someone they care about, whether in love, career, or friendship."
Non-monogamy is inconceivable to this conventional, serious, and habitual sign. "They're earthy and like to know where their next kiss or hot supper is coming from," adds Honigman.