The girl will talk to the boy and the girl would become jealous because she's talking to the boy. They end up spending a lot of time together afterwards. Because they are both attracted to each other and they finally end up going out afterwards and everything falls in place
Forking rivers or paths are commonly used to express a character's opposing features in literature. In this case, it represents Nikolai's two sides - stern and caring. The river merges into one at the end - implying that his two sides can coexist.
