Time and fate have different plans in everyone's life. People became toys its hands and suffer a lot till they get the happiness they deserve. Ishu is happy at least to see Arjun after this much time. She still loves him like a madwoman. He still affects him the same way he did the day one. Even though she wants to hurt him like hell for marrying Shagun and move on in his life, she just can't do that as it will be a bigger punishment to her than him.
All of them meeting each other after this much year's gap, there must be something to solve more. It feels like they have not met for no reason. But what can happen for real? Shagun jas has no idea as to why Ishu has returned to their life.
Shagun always told Arjun that she would never snatch Arjun from his Ishu. She will be going back to her life once Ishu comes back. But 25 years already passed and Shagun can't leave him now. Arjun has become a bad habit for her.