They could start with a misunderstanding. Maybe Prince Gumball misinterprets something Princess Bubblegum does. But as they talk it out, they begin to see each other's perspectives more clearly. Then, they could have a series of small adventures together. Like exploring a new part of the Candy Kingdom that no one has ever been to. In these adventures, they share their fears, hopes and dreams, which gradually brings them closer. And perhaps they could exchange small gifts or tokens of appreciation that are meaningful to them, like a special - made gumball or a piece of unique gum.
The relationship can be developed through shared challenges. For example, if there's a sudden flood of chocolate in the Candy Kingdom that's endangering the lives of the gummy citizens. Prince Gumball and Princess Bubblegum have to work together to build dams and barriers. During this process, they rely on each other's strengths. Gumball might be good at coming up with quick - fix solutions, while Bubblegum is great at long - term planning. This mutual reliance can deepen their relationship.
One way to develop their relationship is through cultural exchange. Prince Gumball could come from a part of the Candy Kingdom where they have different traditions compared to Princess Bubblegum's area. They could start by teaching each other about their respective cultures. For instance, Gumball could show Bubblegum the unique gumball - making ceremonies in his region. And Bubblegum could introduce Gumball to the complex gum - based architecture in her kingdom. Through this exchange, they not only learn about each other but also start to respect and care for each other more, which in turn develops their relationship on a deeper level.