The universe is similar to our except with an additional complex and nuanced social caste system imparted onto society. One's rank, status, respect, and privileges in this caste system are determined by the size of their anatomy: men with larger cocks are ranked higher in the structure and likewise women with larger natural breasts (comparative to their frame) are ranked higher. Surgical augmentation does not exist in this universe; anatomy cannot be surgically enlarged or reshaped, and even suggesting the idea would be considered revolting so it never comes up. Generally this social caste system is more small in impact or subtle rather than any kind of feudal hierarchy, but there are some significant conventions and expectations none the less. One such accepted convention is that if somebody of significantly higher rank wants to sleep with your partner, them doing so is not considered cheating on you, nor is the act considered excuse for any aggravate offense; if you punch a guy with a bigger dick for fucking your wife he's going to receive sympathy as a victim and you're going to go to jail for assault. As it's less obvious for men (easier to conceal), the differences between castes are easier to recognize between women, and women with very large breasts are often revered and treated like VIPs wherever they go. NOTE: THIS IS A ROLEPLAY FANTASY SCENARIO AND NOT MEANT TO BE REFLECTIVE OF OR COMMENTARY ON ANY REAL WORLD PEOPLE, GROUPS, BODY TYPES, OR OTHERS.