Well, in many of these fanfictions, at first, Sirius is a bit wary of Hermione. He's been through a lot and isn't used to having someone so young and seemingly innocent be so involved in his life. But Hermione's determination wins him over. As they spend more time together, they start to understand each other better. Hermione learns about Sirius's past traumas and he discovers her hidden strengths. Their relationship evolves into a very strong bond, whether it's a platonic bond of friendship and mentorship or, in some cases, a romantic connection. For instance, they could be in a situation where they have to rely on each other completely to survive a dangerous encounter with a powerful dark wizard, and this experience cements their relationship even further.
Often, it begins with Hermione trying to help Sirius deal with his post - Azkaban trauma. She uses her knowledge and compassion to reach out to him. As he heals, he starts to see her in a new light. Their relationship then grows as they start to understand each other better. The lemon parts usually are used to explore their more passionate and private moments, which are often written in a very tender and intense way, adding a new dimension to their relationship.
There are fanfictions where Hermione stays with Sirius after he escapes from Azkaban. In these stories, Hermione often uses her intelligence to help Sirius adapt to the modern wizarding world again. She might teach him about new spells and magical devices that have been developed since he was imprisoned. Their relationship in such fanfictions can be one of mutual respect and learning, with Sirius sharing his knowledge of the old - fashioned magic and Hermione introducing him to new concepts.
In many of these fanfictions, the relationship development is centered around the shared responsibility of the pregnancy. They begin to rely on each other more. Sirius, with his experience in the wizarding world, protects Hermione from the potential negative reactions of others. Hermione, in turn, uses her intelligence to plan for the future. They also have tender moments where they bond over the little things, like feeling the baby's first movements or choosing a name for the baby. This helps to build a deep and loving relationship between them.
Their relationship might start off rocky due to the forced nature of the marriage law. Sirius could be overprotective at first, seeing Hermione as someone he needs to shield from the dangers of his world. Hermione, on the other hand, might be frustrated by his overbearing attitude. But as time passes, they learn to communicate better and understand each other's strengths.
Some fanfictions show their relationship developing in a more emotional way. They might discover they have similar traumas from their pasts, which makes them bond on a deeper level. Sirius could open up to Hermione about his time in Azkaban and how he felt being wrongly accused. Hermione could share her experiences of being an outsider in the wizarding world. This mutual understanding helps their relationship grow into a strong and loving sibling bond.
It develops in a complex way. There's a lot of mutual understanding and support growing between them.
In fanfiction, Hermione and Sirius could have a mentor - mentee relationship. Sirius, with his knowledge of the wizarding world and his rebellious nature, could offer Hermione a different perspective on magic and the fight against the dark side. He might share stories of his time in the Order of the Phoenix that would inspire Hermione in her own battles against evil.
At first, their relationship might start out as a simple acquaintance - type thing. Sirius sees Hermione as a smart young witch, but as he comforts her more, they start to develop a deeper bond. Maybe they start sharing secrets about their past traumas.
One popular story might be 'Forbidden Bonds' which explores a unique relationship between them. It delves deep into their characters and how they might interact in a different way than in the original series. The author creates a lot of tension and drama, making it an engaging read.
A father - daughter like relationship could be expected. Sirius, having lost so much in his life, might see Hermione as someone he can care for and protect, much like a daughter. He could be very protective of her and give her advice on how to navigate the complex wizarding world.