part of it is abhi's own doing. He should be aware of things he is doing can be misunderstood by others and make them miserable. especially simi who is always insecure and vulnerable to the emotional atyachar by manju, neetu and anuj. But voted yes abhi is treated horribly by manju which he does not deserve. Simi should trust him but she can't help it seeing abhi with mili. she is also driven and forced by manju to do which she is avoiding.
Simi always ponders and keep things inside bottle up till it all explodes one day.
I mainly blame manju for it all. She brought this upon her house and in simi;s life.