They say there is nothing after marriage and here they are showing there are more interesting things after marriage and breakup.
Dev's mind is full of Sona and he constantly watches her through that broken wall while Sona minds her own business.
Dev wants to provoke her and is mad when she keeps her cool and taunts him softly.
Sona is fire that is melting Dev inside and all his outside anger is just to cover up his real feelings.
He locked her but he is waiting impatiently for her call. Sona's idea of fire worked well and created the required drama.
And Ishwari started cooking.
Who are we to judge them? Let us enjoy the drama created by them for our entertainment.