It was interesting to watch.
Siddharth wants to know what lie he told her. And saying suni sunayi baathom par aap vishwas kaise kar lethe ho. He wants to talk and clear the misunderstanding. When siddharth said Sab kuch, I felt that he was serious. And when she asked out of the way jaake kuch karne keliye, he said that har baar nahi. His version is he did something for her out of the way jaake but she forgot it and he said kuch cheze yaad rakhte ho kuch cheese nahi convenience k hisab se. Her version is he lied to her. And she got his lie. There is a big misunderstanding here.
Siddharth can't keep quiet when he is around her. He also can't take that she ignores him. We also saw Rashami tries very much to ignore him. Rashami can keep her calm in difficult situations. He can't withstand her being with Arhaan/Paras/Vishal.