Callie and Jamie haven’t always been solely focused on each other. Callie developed major feelings for her roommate, Gael Martinez, before he found out he was about to become a father with another woman.
At first, Callie was extremely patient with Gael, even though he had impregnated someone else. But eventually, things fell apart.
Source: https://www.distractify.com/p/are-callie-and-jamie-getting-back-together