I know lately all our expectations have been crushed to dust by the makers but still I am gonna state the reason why I think that today's precap could be a dream. Agar yeh ek last hope bhi kal ke episode ke baad na rahi toh aur kuch kehne ko nehi bachega.
1. Raghav, Aai, Farhad, Amruta, Amma....literally everyone was present during the dance. Ab itne sare log itna bhi kya dance mein engrossed honge ke itna bara aadmi Pallavi ko utha ke le jayega aur unnko bhanak bhi nehi lagegi
2. Mandar saw RaghVi hugging, which must have infuriated him and he wanted to even with Raghav by drugging Pallavi and tarnishing her izzat. So, he spiked Raghav's kheer with some loose motion medicine or something. Then, when the dance started he imagined how the whole thing should play out.
3. About Sunny's reaction in the precap, it could be taken out of context. We are well aware that the precaps are never sequential. Additionally, I felt that reaction was not from when Mandar was taking Pallavi upstairs because he wasn't smirking or evilly smiling. To me, it seemed more like he is worried because his plan just failed and Raghav is the one who is taking Pallavi upstairs. He seemed worried that now Raghav will investigate the matter.
4. Achchha chalo maan lia ki Raghav wasn't around and Mandar indeed locked the room with Pallavi inside. Toh phir when she will wake up, won't she ask why he locked the door etc etc? Then toh his intentions will be clear in front of her. She will definitely leave D house after that and Mandar's whole plan will be foiled. But from the BTS, we already know that Pallavi is still living there. Thus, aisa nehi hua hoga.