In classical literature, there are certain passages in 'The Arabian Nights' that can be seen as having elements of what might be called 'erotic exibition stories'. These stories were often used to explore different aspects of love, desire, and cultural values, but they were also veiled in a lot of symbolism and storytelling devices.
In some cultures, 'erotic exibition stories' can be a way to express the freedom of sexual expression within certain boundaries. For example, in Western cultures, some literature and art that contains elements of this might be seen as a celebration of individuality and the exploration of human desires.
The main distinction of porn with a story genre from regular porn is the presence of a coherent narrative. Regular porn often jumps straight to the sexual action, while the story genre tries to add some kind of story framework around it. But in the end, both are adult-oriented and feature explicit sexual content.
Well, it's hard to say for sure. The concept of 'porn-like' is quite subjective. Some might consider certain novels with excessive sexual descriptions as such, but it depends on individual perspectives and cultural standards.
In many places, 18+ porn comics are considered illegal. This is because they can have a negative impact on society and violate moral and legal standards.