Su Min and Yeon Lu were so engrossed in deciding on how to inform Jun Pyo about Li Wei's threat that they didn't notice that Jun Pyo has indeed arrived.
He wanted to surprise Su Min but he was surprised himself by the conversation that was going on between Su Min and Yeon Lu.
He was shocked to find out that Su Min has contacted Li Wei behind him.
He didn't hear all what they have been discussing before he only heard when Yeon Lu was asking her to promise her that she will inform him about Li Wei's threat and she shouldn't hide something so important from him.
He thought he has gained her trust but he soon realized how wrong he was. She still hasn't trust him fully.
He was hurt by this realization. But he masked his expression by pretending not to have heard their conversation. But he was determined to make her fall for him and not give room for Li Wei to return.