It could improve their relationship. Severus, seeing Harry as a victim of abuse, might start to see past their previous grudges. He may become more of a mentor figure to Harry, guiding him and protecting him from further harm.
Their relationship could become more complex. Severus might be torn between his old feelings towards Harry and this newfound sympathy. He may act coldly on the outside but secretly keep an eye on Harry to ensure his safety. This could lead to a lot of internal conflict within Severus.
Severus could feel a sense of guilt. He might think that he should have been there to prevent it, especially if the abuse is related to the wizarding world's problems that he has some knowledge or influence over. He may then start to take steps to help Harry get out of that situation, like using his skills in potions to heal any physical or mental wounds.
At first, it would be extremely strained. Severus has a history of being at odds with Harry. But with the baby in the picture, they would be forced to interact. Harry might see a different side of Severus as he tries to be a father. Severus, on the other hand, would have to deal with his own feelings towards Harry while also caring for the baby. Over time, they could develop a bond based on their shared responsibility and the love for their child. This would be a huge transformation from their previous relationship which was full of mistrust and dislike.
At first, their relationship would be full of hostility. Harry would be angry about being forced into this marriage with Severus, who he has had a complex history with. Severus, on the other hand, might be indifferent or even disdainful.
They could start by rebuilding trust. Severus could prove his commitment to Harry and the unborn child by protecting them from any threats. Harry could also show forgiveness by allowing Severus back into his life gradually. For instance, Severus could help with preparing for the baby's arrival, like setting up a nursery. This shared responsibility could help mend their relationship.
Their relationship would become more symbiotic. Harry, as the'master', would have a sense of responsibility for Severus in his pet form. This could lead to Harry seeing Severus in a different light, less as the strict professor and more as someone vulnerable who needs protection.
Severus might initially be shocked. He could then feel a sense of protectiveness over Harry. He might start to secretly look out for Harry, like making sure he has enough to eat at Hogwarts and is safe from further harm.
The relationship may become more complicated. Severus might struggle with his own emotions. He might feel an urge to protect Harry from this fictional abuse, but at the same time, he has to deal with his long - standing animosity towards Harry. So, it could lead to a very strange and tense dynamic between them, with Severus trying to balance his new - found protectiveness and his old grudges.
Snape's relationship with Harry could become more complex. He might start to see Harry as more than just Lily's son. As headmaster, he has to ensure Harry's safety and development. This could lead to some awkward but necessary conversations between them. Snape may also use Harry as an example to show the other students what it means to be brave and stand up against evil, which in turn makes Harry see Snape in a different light.
His personality also becomes more open. He has to communicate with Harry in a more honest and open way. He can't keep all his thoughts and feelings bottled up like he used to. He has to share his wisdom and experiences with Harry, which in turn makes him more approachable and less of the brooding, closed - off person he was before in the official story.
Often, fanfiction will explore the idea of Lily having a deeper understanding of Snape's actions and motives. This can lead to a relationship where she is more forgiving and empathetic towards him. For instance, in some stories, when Snape is bullied, Lily steps in more actively to defend him, which changes the dynamic of their relationship. In other cases, the relationship might be reimagined in a romantic way that was only hinted at in the original. There could be a scenario where they actually start a relationship during their Hogwarts years, which would completely change the course of their individual lives and how they interact with other characters like James Potter.