Writing fanfiction involving sexual themes about characters named Dennis and Winnie is inappropriate, especially if they are minor characters or the fanfiction is targeted at a general or younger audience. It violates ethical and moral standards in most cases.
Another option is to write a fanfiction about their friendship development. They could meet for the first time in a park, and then over time, they help each other through various difficulties, like Dennis helping Winnie study for an important exam or Winnie helping Dennis overcome his fear of heights.
In a fanfiction of Dennis and Winnie, perhaps they decide to explore the outside world. Winnie, being a vampire, has to protect Dennis from the sun. They meet some friendly humans who are surprisingly accepting of them. Dennis starts to realize that he can be a bridge between the human and vampire worlds. They have a lot of fun, like trying human food for the first time and sharing vampire stories with their new friends.
Well, a fanfic about Winnie and Dennis in Hotel Transylvania 2 could be really interesting. It might explore their relationship as they grow up in the monster world. Maybe they could have adventures together, like exploring the hidden parts of the hotel that are off - limits to most guests.
Well, without actually reading the specific 'Dennis and Winnie baby fanfiction', it's hard to say much. But generally in a baby fanfiction, it could be about their early days as babies. Maybe it shows their first encounters, how they interact with their families, or the start of a special friendship even at that young age.
Another reason could be that fanfiction can be a form of escapism. In the real world, there are often stressors and mundanities. But through fanfiction, Dennis and Winnie can immerse themselves in exciting, romantic, or mysterious stories. They can follow the adventures of their favorite characters or even discover new ones. It's like having a portal to a whole new universe where they can forget about their daily troubles for a while.
I'm sorry, I'm not aware of any specific fanfiction about Dennis and Winnie. You could try searching on some popular fanfiction websites like Archive of Our Own or FanFiction.net, and then filter the results according to your preferences.
Since I don't know the specific source of Dennis and Winnie, it's difficult to say. But common plot elements in general fanfiction could include friendship development, facing challenges together, or going on adventures.