Well, in aziraphale x crowley overstim fanfics, a frequent theme is the clash of their two worlds. Their angelic and demonic backgrounds create a lot of tension and potential for overstimulation. It could also be about the new sensations and emotions they encounter when they step out of their normal comfort zones. For example, when they interact with human concepts in a more intense way than usual. This can lead to a series of events that test and expand their relationship.
I'm not sure specifically about 'overstim' fanfics for aziraphale and crowley. But you can try searching on popular fanfic platforms like Archive of Our Own. There are likely many well - written fics about them with different themes and styles.
It's hard to say if they are extremely popular in a general sense. While there is a large and diverse fan community for Good Omens, not everyone is interested in this particular type of fanfic. Some fans might be more into the romantic or adventure - based fanfics about aziraphale and crowley.
Well, a lot of Crowley x Aziraphale fanfics focus on their unique dynamic. Some fanfics might show them going on adventures together that are not part of the original story. These adventures can range from solving supernatural mysteries to just exploring the human world in a more in - depth way. And then there are those that focus on the emotional development of their relationship, like how they come to truly understand each other on a deeper level.
One common theme could be the idea of indulgence. Since belly stuffing implies over - eating or excessive consumption, it might explore how Crowley and Aziraphale experience indulgence in a new way, perhaps as a form of relaxation or a break from their usual celestial/demonic duties.
One common plot is that Aziraphale has to take care of Crowley after he gets injured in a battle against some other supernatural forces. This often involves a lot of tender moments as Aziraphale tries to heal Crowley using his angelic powers or with the help of some magical items.
Common themes include love against all odds. Given their different backgrounds and allegiances, their love story in fanfic is often about overcoming obstacles. Also, self - discovery is a theme. As they explore their relationship, they also discover new things about themselves. And there is often a theme of secrecy, as they have to keep their relationship hidden from others in the fanfic narratives.
One common theme is the clash of their different natures. Crowley being a demon and Aziraphale an angel, their approaches to parenting can be very different. Another theme is the discovery of love in a non - romantic but still very deep family - like way.
Another reason could be jealousy. In some fanfics, they might both be interested in the same person or thing, and Aziraphale's actions might seem unfair to Crowley. Say there's a powerful artifact that Aziraphale wants to give to Heaven, but Crowley thinks it should be kept out of the hands of both sides. So Crowley yells out of frustration.
You can start by looking on popular fanfic websites such as Archive of Our Own. Use the search function and type in 'Crowley x Aziraphale'. You'll get a list of relevant fanfics. You can also check fan communities on social media platforms like Tumblr or Reddit. People often share and recommend their favorite fanfics there.
One common theme is his relationship with Crowley. Their friendship/relationship is often explored in different ways, like how they support each other through various challenges in the apocalypse - related events or in a more domestic setting.