Another place to look is on some dedicated Mario - related forums. There are often sections where fans share their own written works about the characters, and you're likely to find some Bowser and Bowser Jr fanfiction there.
You can try fanfiction websites like Archive of Our Own or FanFiction.net. They have a wide variety of fan - created stories, including those about Bowser and Bowser Jr.
Some gaming forums also have sections dedicated to fanfiction. For example, Nintendo - related forums might have threads where fans share their Bowser Jr. and Bowser fanfics. You can interact with other fans there, too, and maybe even get some recommendations based on what others have liked.
Some gaming - related forums might also be a good place to look. Gamers who are fans of the characters might share their own fanfiction creations or know where to find some good ones. For example, if there are forums dedicated to the game that these characters are from, it's likely that someone has written or can point you towards some Bowser Jr. x Cody fanfiction.
I'm not aware of any specific place dedicated solely to Bowser Jr. gay fanfic. However, some general fanfic websites like Archive of Our Own (AO3) might have such works if they are in line with their content policies.
You could also try checking out some Nintendo - specific fanfiction forums or communities. These places might have members who are really into creating or sharing stories about unique pairings like Bowser Jr. and Inkling Girl. Sometimes these smaller communities can have some hidden gems that you won't find on the bigger platforms.
Some fanfictions might take a more comical turn. Picture Bowser and Bowser Jr trying to host a party in their castle but everything goes wrong. From the invitations getting lost to the food being ruined, it's a hilarious take on their characters.
In some fanfics, there might be a plot where Bowser Jr. tries to prove himself to Bowser. He might take on a difficult task on his own, like stealing a precious jewel from a well - guarded castle. This shows his growth and determination to be a worthy heir to Bowser. And it also adds a touch of family - like relationship exploration between them.
One possible theme could be family. As Bowser and Bowser Jr. are father - son, the fanfic could explore the dynamics of their family relationship. It could show how they support each other, or how Bowser is trying to raise Bowser Jr. to be a worthy heir.
One interesting fanfic could be about Bowser Jr. going on a solo adventure to prove himself to Bowser. He might encounter some of Mario's friends and have to use his wits to get out of tricky situations.
Growth and self - discovery are also common themes. He might start as a bit of a troublemaker but through his experiences in the fanfiction, he learns more about himself and grows as a character. Also, friendship can be a theme. He could make unexpected friends during his adventures, which helps him see things from different perspectives.
Some social media groups dedicated to Mario fandom might also be a good source. For example, on Facebook or Reddit, there are groups where fans share their own 'bowser and peach fanfiction' or discuss their favorite stories. You can interact with other fans and get recommendations on where to find more interesting reads about this pairing.