Carrie and Aidan didn't just break up once on Sex and the City, they broke up twice after meeting in season 3. While Carrie was known for her on-and-off relationship with Mr. Big, Aidan Shaw was the next big love in her life. After meeting him at a furniture show, they took their relationship slow, which Carrie wasn't used to. Aidan wanted to build a friendship with Carrie before taking their bond to the next level. In the end, Carrie fell in love with him for the care he put into their relationship.
As was the case with every new boyfriend of Carrie's on Sex and the City, she had to turn down Big when she and Aidan became serious. This turned out to be harder than she realized, and it's where the problems in her relationship with Aidan started. Aidan never saw a breakup in their future, but Carrie knew she wasn't capable of a relationship as long as Big was around.
Carrie & Aidan First Broke Up Because She Cheated On Him
Despite dating Aidan, Carrie kept running into Big, and it made her question her relationship. Though she loved Aidan, she gave in to her instincts in Sex and the CIty season 3, episode 9, "Easy Come Easy Go," when she slept with Big. After doing so once, she continued sleeping with Big secretly, and an affair began. At the time, Big was married to Natasha, which created even more of a scandal since both parties were in relationships.
At the time, the only problems Aidan and Carrie had were Aidan's views on Carrie's lifestyle. He thought she had too many shoes and smoked too much. With Big, Carrie could be her true self. However, the affair became all-encoming and Carrie couldn't sleep at night. On the day of Charlotte's wedding, Carrie told Aidan that she cheated on him with Big. Instead of making it work because he loved her, Aidan broke up with Carrie and she stayed single to mend her heartbreak.
Carrie & Aidan Broke Up Again Because She Wasn't Ready To Marry Him
A season later, Carrie and Aidan got back together after he opened a restaurant with Miranda's boyfriend Steve. Even though Aidan still loved her, he resented Carrie for her worst mistake on SATC: ruining their relationship and Big's marriage. Aidan thought he could move on, but he wanted Big out of her life for good, which she couldn't do. With Big still in the picture, Aidan proposed to Carrie to stake his claim.
Newly engaged, Carrie didn't have the same excitement as most brides. Instead of wearing her ring on her finger, she wore it on a chain around her neck. Carrie tried to slow down their relationship, but Aidan saw through her cold feet and knew she'd never be ready to marry him. After being too pushy about marriage, the two broke up for good. At the end of Sex and the City season 6, Carrie was through with Aidan and focused on Big, proving that she and Aidan wouldn't have worked out for the long haul anyway.