Test in love is not only based on trust, it is based totally on the foundation of love, and how the love laid that foundation of love between two fanatics decides the groundwork on which their love should be tested.
"I am her solely inamorata and no one else can take my place." Vansh said when Zain spoke that Vansh should understand about Riddhima's lovers.
Then some unknown character entered the Mansion. The noise of his footsteps was echoing who faced Siya just as he stepped inside excitedly, "OMG!"
He glanced at her and moved ahead. He was unknown to all and the purpose behind Siya's reaction this way, is also not known.
Furthermore, he was like normal boys, as can be guessed by way of his appearance. There was nothing special in him. He simply came holding an envelope in his hand.
On the same hand, Zain was announcing to Vansh, "Nobody will take your place if you'll timely keep her. The choice is yours."