How did seaweed know Song Siming and Beckham in Dwelling House? What is the ending?

Seaweed and Beckham: Seaweed and Beckham work in the same building, but on a rainy day, Beckham met seaweed flying in the rain with an umbrella at the door of the building, so he took the initiative to hold an umbrella. In this way, they met and fell in love. Seaweed and Song Siming: Seaweed just joined a real estate development company and became an ordinary employee. One day, she accompanied the company boss Chen Sifu to socialize. In fact, seaweed went to socialize with a depressed mood that day. During the dinner, Song Siming talked with the distraught seaweed and learned that she was not married. Then she fell in love with seaweed.