Hindi TV Serial - Iss Pyaar Ko Kya Naam Doon - The sudden marriage of Khushi and Arnav shocks everybody

During the time when the pre-marriage ceremonies of Akash and Payal are happening, there was a lot of other drama happening in the house. Arnav had seen Shyam and Khushi in a way that he thought that they were both in love with each other, and after a conversation with Shyam, he was further convinced that both of them were responsible for his sister getting cheated; and further, if his sister Anjali was not pregnant, he would have ensured that this would not have continued. However, he had to ensure that his sister did not suffer because of this, and as a result, he had to ensure that Shyam stayed with his sister and did not have a chance to try for Khushi again.
So what did he do ? He decided that the best way to ensure that Khushi was no longer available for Shyam, and towards that effect, he decided that marrying Khushi would be the solution. Now, it is not that Khushi would be immediately ready to marry him at such short notice. So, he decided to use force, by threatening Khushi that unless she agreed to marry him quickly, he would ensure that the marriage of Payal and Akash did not happen, and this would mean a disaster for Khushi's sister Payal. In the end, faced with this tough choice, Khushi agreed to this and they got married in a temple and came to the marriage of Akash and Payal like this.
This was a shock to everybody in the family, and they had a lot of queries about this. However, Arnav walked away, refusing to answer any queries, even when they were asked by Anjali. And then, when Khushi is asked, she refused to also answer even though she is deeply stressed, and has to bear the anger of everybody, including that of her own sister Payal. Further, she is reminded that she was actually an orphan, and that relations with her are being broken off.
She tries to get answers from Arnav as to why he was trying to do that, but there is no answer that she is getting from Arnav, and is very stressed at all this.