Nadia rejected his nice whim, because he hasn't been nice to her for quite a while now. His nice "responsible adult" front is all a show for the other housemates. I know Jason would speak differently to her if they were 1-2-1, he would be slightly warmer maybe. But don't forget Day 20 where we clearly witnessed the weak, out of control with anger, Jason.
I think Jason is just nice to women he wants to ****