The affair arc—where Carrie cheats on Aidan with Big—is a masterclass in moral ambiguity. The show refuses to paint Carrie as a villain, but it also refuses to let her off the hook. The elevator scene (Aidan silently pounding the wall) remains one of the most visceral depictions of betrayal on TV.
Aidan is perfect on paper. He is a furniture designer (creative), loves dogs (empathetic), and wants to get married (committed). He builds Carrie a custom desk, forgives her affair (eventually), and buys the apartment next door to merge their lives.