Rubina is fake absolutely..
Example - Her house bond with Nikki she hardly stopped her from doing wrong.
Real relation- For her real sister she said words like we are not like that , don't do this don't do that..
That right there proved her fakeness for Nikki which is probably only for game
For Jasmine to Salman and everyone kept saying I liked her but in reality she had so much problem with Jasmine, always blurted out to her husband things like Jasmine did this that basically bitching n then the famous khoon ka gooth just cos of Jasmine
Nikki is a contestant & playing her own game with her full consciousness. She is fully aware of what she is doing & she intentionally becomes badtameez ( the word which is coined for her by Salman & the contestants) so as to give content & remain in the game. Who is Rubina to stop her from going overboard & why should she spoil Nikki's game? Also at the start of the show when Nikki was very much against Abhinav & Rubina & was friends with Rahul , Pavitra, Eijaz & others why didn't they stop her from doing wrong? She has not being doing anything different pre & post her elimination. Even Salman at that time had found her similar kind of antics & attitude admirable & gutsy & good content for the show. So basically it means all their views & opinion about the badtameezi ( again the word used here is not mine) that Nikki does is dependent on whom she is friends with. Isn't that unfair & illogical? And it is not that Rubina doesn't give her advice, we have seen many instances where Rubina has advised her but Nikki has ignored it & done her own thing. And rightly so, otherwise she would be called a puppet of Rubina. Also Nikki herself has admitted last week that she does all these badtameezi in the show just to remain in the game otherwise she would have been voted out by the audience right at the start.
Regarding Jasmin, it is Jasmine who had first backstabbed Rubina & would speak negative against her & try to pull her down. Rubina ignored it for a long time & behaved normally with her & still considered her a friend until it became too obvious that Jas was not going to stop her negativity against her. That is when she started giving it back to her. Also it was Jas who would invariably start the fights & accusations & Rubina would react to it by giving it back to her. Jas continued with attacking, bad mouthing her to everyone even after coming back to BB as Aly's support. It is obvious anyone would lose his/ her cool when someone is unreasonable & attacks you 24 hours at a stretch just because the person is jealous & insecure about you. And Rubina needed an outlet to vent out her anger & grievance against Jas' growing negativity & she did that with Abhinav. I wouldn't call it bitching.