On the other hand, some fans might be interested in seeing how the author develops the story from such a controversial starting point. They could be curious about how Pepper will respond and if there's a chance for redemption for Tony.
I'm not sure if there is truly 'good' fanfiction in this regard as it goes against the general positive relationship depicted in the main story. Fanfiction often contains a wide range of interpretations, but this particular theme might not be in line with what most fans expect from the Pepper - Tony relationship.
It could be that Tony is under some sort of mind - control or influence that makes him cheat on Pepper. Then the story might focus on Pepper's journey to break the control over Tony and save their relationship.
Maybe the writer wants to explore an alternate view of Pepper's character. They could be showing that she has flaws and isn't the perfect partner all the time. It could also be a way to introduce new characters into the story in a more impactful way, like the person she cheats with.
At first, Tony might be in denial. He's so used to having Pepper by his side that he can't fathom her leaving, especially when she's pregnant. As time goes on, he could become very sad and start to reflect on what he did wrong in their relationship. He might try to win her back, using his resources and intelligence to show her that he can be a good partner and father.
On the other hand, there could be fans who are interested in seeing the drama and conflict that would come from this. They might enjoy seeing how the characters would deal with such a complex and emotional situation. It could also open up new ways of exploring the personalities of Percy and Artemis.
The reaction among fans would be quite mixed. Some die - hard fans of the original series would be appalled as they have a clear image of ChiChi and Goku's relationship. They would see this type of fanfiction as a perversion of the original concept. On the other hand, there are those who are more open - minded and might see it as an interesting, if not controversial, exploration of the characters. But overall, the negative reactions would probably outweigh the positive ones.
Pepper might be in shock at first. She could be speechless and just stare at Tony in disbelief.
Some fans would be outraged. Carlisle and Esme are a beloved couple in the Twilight series, and the idea of Carlisle cheating goes against the image many fans have of his character. They might see it as a desecration of the original story's relationships.
Some fans would be outraged. Edward and Bella's relationship is iconic, and any deviation from their loyalty to each other would be unacceptable to them.
There are other fans who are interested in exploring different storylines. They see it as a creative way to expand the Twilight universe. They might enjoy seeing how the characters would react in such a difficult situation, even if it's not in line with the original story.