So Nandini will keep reminding Manik of how he hurt her, not in a malicious way. But in a way that constantly remind him how she doesn't trust people anymore because of what he did. He'll keep thinking how he broke her. And he'll be breaking inside. It's going to only get worse with time. He's going to start destroying himself, whilst Dhruv will become "Nandini's shoulder to lean on".
Dhruv's going to propose, but he'll talk about how when he told Manik, he supported him instantly when he came to know about Dhruv's love. Nandini's going to be shocked and might ask when. When Dhruv tells about his setup of that tent and lights, she's going to connect the dots.
She's going to confront Manik, and although he's going to deny it, she'll finally see his pain too. But she won't forgive Manik, not that easily. She'll see how much steps back manik's is going to take. Make him jealous, see if his resolve breaks.