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.
In some fanfictions, Bakugo can become more empathetic. For example, if he experiences a situation where he realizes the pain he's caused Deku over the years. His aggressive nature might soften as he starts to understand Deku better. Deku, on the other hand, could become more assertive. Instead of always being the timid one, he might stand up to Bakugo more firmly in fanfiction scenarios.
Another theme is the exploration of their differences. Shigaraki represents chaos and destruction while Deku represents hope and heroism. Fanfics usually explore how these two opposing forces interact and influence each other. For example, in some fanfics, they start to understand each other's perspectives better as they spend more time together.
One common theme is friendship. Despite their initial rivalry, fanfics often explore how Bakugo and Deku form a deep bond. Another theme is growth. They both grow as heroes and as people in these stories. For example, Bakugo learning to control his temper and Deku getting stronger.