Though Parth looks disturbed and in dilemma because of Teni's feelings now, he won't be in that state for long. Once Teni gets married and moves to US, he will gradually be back to his routine life, because he doesn't have any dilemma in his mind regarding his feelings for Teni and Shorvori. He is very clear that he cares for Teni just as a friend and nothing else, and that he loves only Shorvori and can never give her place in his life to anyone else.
The way Parth is dealing with the situation right now, it right from his POV. The marriage is just a few days away and if anything wrong happens, his entire family including himself, his wife and Aman will be broken.. So he can't take the risk of provoking Teni purposely, especially when he thinks that Teni is trying to move on and Aman is right choice for her. He is absolutely right in assuming that even Teni doesn't want anyone to know about her feelings, because none of Teni's actions have indicated that she wants her feelings to come to fore and to disturb her as well as PaRi's life.
As Sudha wrote, Parth has indicated through his actions that he is happy in his life with Shorvori, and wants Teni to be happy with Aman in a similar way.. Despite that if Teni is not realizing and wants a further closure to her lovestory, isn't it her responsibility to talk to Parth and get things cleared? How is it Parth's responsibility to give her that closure when he doesn't actually know what is going in her mind??