Before Sin asks Vidya to show some evidence, Sagars eyes said it all. In his hearts of hearts, he does believe her. Watch that one scene after the 1st break (& repeat of the first 5mins), where Vidya reminds him that when he had a headache, she would massage his head for him, they would play with Sameer together. The best part was when she said what we all feel about SV....that they can't live without each other and they need the other.
But Sin maata ko butt in karna hi para!!!