The thing is neither are into that mind-set yet. But that doesn't mean they will never be.
The separation which is in cards in the future might actually end up making them miss each other. See....Tejo is a blank Slate. She doesn't have the baggage of a past relationship or even desire. Jas was a nonentity..she didn't have any sort of feelings for him. She is frankly, inexperienced.
That is not the case with Fateh. Dunno about his past but from last two years he was after Jasso. He craved her and he also shared intimate moments with her. Till that he has been touchy with Tejo too, both as a friend before and later as a husband-friend. But he doesn't desire her that way ...Yet.
The separation might actually turn things in this favour. Touch is a very powerful feeling. And lately her presence and touch calms him. Take that away and he will be frantic. With Jasso back and separation, he will begin missing her. Her lack of presence will open a hole in him and to somehow mitigate it, he will search for her touch. Will start craving her.
Hand holding, tucking the hair strand, sudden brush of skin, holding her face in his hands, hugs....these things will follow. If the way Fateh is shown right now goes on...he will begin craving for her like a man thirsting for water in a desert.
For this...Fateh has to be the instigator because Tejo would never instigate this with him. Only if he takes the first step, Tejo will reciprocate.
However once both do so....they will be fire.