The progress between Ian and Jo relationship is honestly so nice to see. You really just get to see how Jo has taken Ian so far. The same Ian who never went stargazing or on dates is now clinging to Jo, just like how Jo cleans onto him and is even afraid that he'll have to leave Jo's side once Jo goes to college. It's nice and endearing to see how much a person can change if they find someone who loves them, takes time to care about their feelings, and is not just mindlessly making decisions for the both of them.