No way. The manga portrays their connection through mutual respect and competition in their journey to become great heroes. A kiss is not part of that narrative at all.
One interesting Deku and Bakugo fanfiction could be where they have to team up for a special mission that no one else can handle. In this story, they start off bickering as usual but gradually learn to trust and rely on each other more deeply.
A common theme is growth. Both characters are on a journey of self - improvement, and in these fanfics, their relationship often plays a role in that growth. For example, they might learn from each other's strengths and weaknesses.
Another theme is growth. Both characters grow as heroes and as individuals. In these fanfics, you can see how they influence each other's development, whether it's in terms of their quirk usage or their mental strength. For example, Deku might inspire Bakugo to be more selfless in battle, and Bakugo might push Deku to be more assertive.