Perhaps Snape realizes that Harry's presence in the tournament is part of a bigger plot that could endanger the wizarding world. He may decide to help Harry in order to uncover the true nature of the plot. By keeping Harry alive and somewhat informed, Snape can use Harry as a tool to expose those who are behind the dangerous schemes in the Goblet of Fire scenario.
One possible reason could be Snape's sense of duty to protect Hogwarts students in general. Even though he dislikes Harry, he might put aside personal feelings to ensure the safety of a student in a dangerous tournament like the Triwizard Tournament. Another reason could be Dumbledore's influence. Dumbledore trusts Snape and may have asked him to keep an eye on Harry during this event.
Snape's help could give Harry an edge in terms of knowledge. For example, if Snape provides some hints about the magical creatures or challenges in the tournament, Harry can better prepare. This might lead to more confident performances in tasks like facing the dragons or solving the maze.
Maybe Harry discovers something about his past, perhaps related to his parents, that only Snape can help with. Snape was closely associated with Harry's parents. He might know some secrets or have some information that could help Harry understand a family mystery or some hidden power within him.
It could be a plot device used by the author of the fanfiction. The touch might be used to create tension or an emotional moment between Snape and Harry. It could signify a turning point in their relationship, whether it's the start of a more positive understanding or the heightening of an existing conflict. For example, the touch could make Harry feel uncomfortable and lead to a confrontation later, or it could make him realize that Snape has a more complex side than he initially thought.
One possible plotline could be that Harry discovers he is in this unexpected mpreg situation and is initially terrified and confused. Snape, despite their past differences, steps in to help because he realizes Harry has no one else to turn to. Snape could use his knowledge of potions to ease Harry's physical discomfort during the pregnancy.
One possible reason could be that Harry is afraid of Snape's intimidating presence. Snape has always been strict and rather unfriendly towards Harry in the original series, so in the fanfiction, this fear might be amplified, causing Harry to run. Another reason could be that Harry has stumbled upon something he shouldn't have seen that involves Snape, and he's running to avoid getting caught.
One possible reason could be Snape's long - standing grudge against James Potter, Harry's father. Since Snape had a difficult past with James, he might project that onto Harry. Another reason could be that Snape is trying to protect Harry in a very strange way. He may think that by rejecting Harry, he is keeping him at a distance from the dangerous wizarding world politics and plots that Snape is often involved in.
One possible reason could be that Snape suspects Harry of something dangerous or against the school rules. Maybe he thinks Harry is involved in some secret Dark Arts activities and ties him up to prevent him from causing further trouble or escaping while he investigates.
Maybe Snape suspects Harry of being involved in some sort of dangerous activity related to the Dark Arts. Pressing him to the wall could be a way to force Harry to come clean about his actions or any knowledge he might have. It could also be that Snape is acting out of his own insecurities and pent - up emotions towards Harry, which he has been suppressing for a long time.
One possible reason could be his lingering resentment towards James Potter, Harry's father. Snape and James had a long - standing feud during their school days. Since Harry looks a lot like James, Snape might be transferring his old grudges onto Harry.
One possible reason could be that Snape shows a different side to Harry in the fanfiction. Maybe he protects Harry secretly from some hidden threats that others are unaware of, which makes Harry start to trust him.