Yang saw Chen's photos on SNS and began to suspect that Chen was dating a female colleague in their company, so he came to ask Yin. Yin thought her brother had discovered her relationship with Chen. Since then, Yin and Chen have been more careful when they go on a date. Yin even asked Chen to sign a love contract and required Chen to strictly comply with the contract. (Source: Viu; edited by MyDramaList)