After watching yesterday's episode one thing came to my mind. The day before Rehan disappeared he was going nuts shouting for Bella and trying make everyone understand that Bella was in danger. And then he suddenly disappeared. When he came back it was Vish and obs she was being very comfortable with Bella as she is her friend.
Mahir's jealousy was very much justified as suddenly someone else is showing concern for his wife. And I really don't think it is wrong to expect truth from your partner no matter how awkward and forced that relationship is especially when the person demanding truth is also being truthful.
Mahir's thought that Bella should be happy, and if her happiness is with someone else he is ready to sacrifice his love for that. He is also ready to sacrifice Jamini's love. That shows he is only human and a flawed one at that. He is not the Aadarsh guy who will support only love. Those people are really fake.
He is not judging Bella for wanting to be with someone else. He is okay with it as long as she is being honest about it. He is also being very selfish when says that he will even seperate Rehan and Jamini too. For him Jamini's love is very true but is willing to make an innocent girl suffer just to make sure that HIS Bella stays happy.
His is a very relatable character and I hope they keep him like that constantly.
PS I know Jamini is not innocent but for Mahir she is.