It's evident that Virat is attracted to Sai although his illogical vaada (itne din baad wo pakao flashback made a re-entry for PP thankfully) has now moved away from his heart to his head. The vaada is more in his head to act as a barrier to any other action that he may 'think' of which will be contrary to it. But what about the involuntary actions? He won't be able to control it.
The touching of the hair-- almost unintentionally done and even Sai did not really mind it. Phir seeng aane se rokhne wali sar ki takkar. It was sweet and simple - it conveys how it is going to be so hard to not fall in love and yet the boundary that will remain.
Chalo, sachhi bolo ACP Saheb, wo Sai ki zulfein aisa kya problem Kar rahi thi that you had to brush her hair strand so perfectly behind her ears in slow motion? Itna time waste Kiya to chipkali bhi bhaag gayi. But kya hua, roka Nahi Gaya na? Apne aap ho gaya? Hota hai..