He might be initially shocked. Snape has deep and complex feelings for Lily. His reaction could range from a moment of stunned silence as he processes the news. He may also feel a pang of jealousy towards the father, whoever that is. Given his love for Lily, he'd probably be very protective in his own way, despite the situation being complicated by their past and his past actions and associations.
Snape's reaction would be highly nuanced. In the fanfiction world, it depends on how the author has developed his character up to that point. If the fanfiction has emphasized his more selfless side towards Lily, he may immediately go into a protective mode. He could start thinking about how to keep her and the unborn child safe from the dark forces around them, especially if the story is set in a time of danger like during Voldemort's rise. He might also struggle with his own internal demons, like his feelings of inadequacy compared to Lily's partner and his own past mistakes that led to their estrangement.
Snape would likely be a mix of emotions. He could be angry at first, not at Lily but at the situation perhaps. Angry that she is with someone else and having a child with that person. But then his love for her would probably overtake that anger, and he might try to offer his support in some way, secretly of course, because of his pride and his own difficult position in Lily's life.
Snape's reaction could be quite mixed. On one hand, he might be angry at Dumbledore for not doing more if he knew about the abuse. He may also feel a strange sort of empathy towards Harry. After all, Snape himself had a difficult childhood. So, he could start to be a bit more lenient with Harry in his classes and try to subtly offer support.
Snape's reaction could be multi - faceted. He might be angry at those who are abusing Draco, but also a bit conflicted because of Draco's family's ties to the Dark side. He could use his position as a teacher to give Draco some extra guidance and support, perhaps in the form of private tutoring sessions where he can also check on Draco's well - being more closely. He may also start to question his own views on the Malfoy family in general.
Sasuke would likely first show a stoic exterior when he finds out. However, internally, he's in turmoil. On one hand, he's happy that he and Sakura are going to have a child. On the other hand, he's worried about the potential dangers his family could face because of his past enemies. So, he might start making plans to keep them safe, like finding a more secure place to live.
Socially, it could be difficult for him. If others find out that he still has feelings for Lily and she's pregnant, he could face ridicule or be the subject of gossip. Also, depending on his relationship with Lily's partner, there could be conflict. He may have to face the fact that he has to keep his distance more than ever to avoid causing trouble for Lily and her unborn child.
Snape might be initially in shock. He had trusted Lily deeply, so the betrayal would hit him hard. He could become very angry and bitter, perhaps vowing revenge against her. He might also close himself off emotionally, not wanting to trust anyone again.
In some fanfictions, Vegeta is initially shocked. He might stand there in silence for a moment, his eyes wide. Then he could feel a strange mix of emotions, like pride and fear. He's proud to be having a child with Bulma but also fears for the safety of his family given his dangerous past and the many enemies he has.
He might immediately go into a protective mode. He could use his potions knowledge to quickly make a healing draught for her. After all, Snape is very skilled in potions, and Hermione being hurt would likely trigger his instinct to help.
In the fanfic, Snape's reaction could be multi - faceted. He might start by investigating the abuse more deeply. He could use his skills as a Potions master and a former Death Eater to find out who is behind the abuse. And then, he might take steps to ensure Harry's safety. This could involve enlisting the help of other teachers or even trying to get Dumbledore more involved. He may also start to teach Harry some extra skills or give him potions to help him deal with the emotional and physical trauma of the abuse.
He might be overjoyed at first. Castle has always been deeply in love with Beckett, and a baby would be like a new adventure for them. He'd probably start making plans right away, thinking about baby names and how to turn one of the rooms in their place into a nursery.
He would probably be in shock. Snape has spent so much time around Harry in one way or another throughout his years at Hogwarts. His immediate reaction could be disbelief. He might stand there frozen for a moment, unable to process what he's seeing. Then, the full weight of the situation would hit him, and he could break down in a rare display of raw emotion.