One possible plotline could be a magical accident. Maybe a spell backfires during a Defense Against the Dark Arts class and Harry is teleported onto Snape's bed. Snape then has to figure out how to reverse the spell while also dealing with his initial irritation towards Harry. This could lead to a series of comical exchanges between them as they try to work together to fix the situation.
Perhaps in this fanfiction, Harry is forced onto the bed by a mysterious force while he's in the Forbidden Forest. It could be related to some ancient magic that the forest holds. He then has to communicate with the forest creatures, like the centaurs or the bowtruckles, to find a way to get off the bed. The centaurs might offer their wisdom about the strange magic, and the bowtruckles could help him find a special plant or object that has the power to break the spell. This would be an adventure - filled plotline that doesn't involve any inappropriate content.
Yes, it's possible. Fanfiction can take many different turns. Some writers could be exploring the idea of forced proximity between Harry and Snape to build a different kind of relationship dynamic. Maybe it's about Harry being magically or situationally forced onto Snape's bed as a means to start a conversation or resolve some long - standing misunderstandings between them, without any improper undertones.
One possible plotline could be that Harry discovers a magical animal that is in danger. He forms such a strong bond with it that it's like they are family. Through some magical event, they create something together that is like a 'baby' in the sense of a new magical entity that they both care for and protect.
A plotline could involve Lucius having a change of heart after the fall of Voldemort. He realizes the error of his ways and tries to make amends. Harry, being the forgiving person he is, decides to help Lucius integrate back into the wizarding society. This could lead to a series of adventures where they face prejudice from other wizards together and form an unlikely friendship.
Maybe it's a political move within the wizarding world. The Ministry of Magic might force this marriage to unite two powerful magical forces. Harry would then have to deal with his feelings for his friends like Hermione and Ron, who would be shocked. Snape, on the other hand, would have to adjust his view of Harry from a student to a partner. They could start to find common ground in their love for Hogwarts and magic in general.
They might be in a situation where they are drugged (accidentally, of course) by some magical potion. As a result, they become drowsy and fall asleep near each other. The story could then focus on how they wake up and try to figure out what happened to them. It could also explore their reactions to waking up so close to each other, with a focus on their friendship and how they handle the awkwardness in a light - hearted way.
One possible plotline could be them going on a special adventure together. Maybe they discover a hidden part of Hogwarts that no one else knows about and they have to work together to solve the mysteries within it. Another could be that they form a study group to master a very difficult spell or subject, and through their combined efforts, they learn a great deal and grow closer as friends.
One possible plotline could be a magical misadventure where Harry and Snape are forced into an awkward situation due to a spell gone wrong. For example, a spell binds them in a strange position as a prank by a mischievous magical creature. Another could be a mind - controlling potion that makes Harry act in this odd way towards Snape, but it's all part of a mystery to uncover who is behind it. And perhaps there could be a situation where they are in a magically - created obstacle course and this strange 'forced to straddle' situation is a part of one of the challenges they must overcome together to save Hogwarts from a new threat.
One possible plotline could be that while Snape is mentoring Harry, some dark magic incident occurs that results in Harry's unexpected mpreg situation. Snape then has to not only continue mentoring Harry in magic but also deal with this strange and difficult situation, perhaps protecting Harry from those who would judge or harm him because of it.
One possible plotline could be centered around the friendship aspect. Harry, Hermione, and Ginny might be worried about how their friendship will be affected by the pregnancies. They could work together to ensure that they still support each other through the changes. Another could be about how the wizarding community reacts. Maybe there are some old - fashioned views that they have to deal with, but they prove everyone wrong by handling the situation gracefully.