Contradictory to what Salman said for Kamya (that she is fed up of Pratyusha), it seems that Arman is really fed up of Tanisha. The way he treats her, shouts her and disrespect her it is very clear that he does not like Tanisha by heart, but only because of history of their relationship he is bearing her.
But why Arman is fed up of Tanisha?
She does not nominate her, she does not back bite her, she always obey her, she defends her... He also must have got the message that BB and Salman are supporting her. Any body would have loved to have companion like Tanisha in present BB's context.
I think Arman has realized Tanisha's reality - her cunningness, or it is a game plan. What do you think. If it is a game plan, it is stupid and not dignified as far as tanisha is concernec.