The development in the comics is quite interesting. Initially, Hulk is more of an enigma to Black Widow. But as she gets closer to the Avengers, she starts to engage with Hulk more. Their relationship evolves as Black Widow tries to help Hulk control his rage. This leads to a growing closeness and a sense of mutual care. There are many story arcs where they rely on each other, which is a sign of their developing love story.