If you see SaiRat as a team/couple, yesterday's behavior is not out of normal. Sai is his wife. He can only reprimand her. Pakhi is a third person, he can feel irritated but not correct her. He doesnt have right to do that. Though as a family member he told her to be reasonable. With his wife, he set the expectations. The room interaction is well directed and enacted. It is so domestic! It was a heated discussion he had with his wife, not a fight. In my opinion.
Actually now, even more than ever, Pakhi is connected to them. She is not a third person because she is carrying their child. As a surrogate father, he has every right to reprimand Pakhi if she doesn't follow the requirements.
Pakhi cannot object to anything Sai & Virat ask her to do.
Definitely he can trust Sai's instincts as a doctor & a mother and calm her down, by admitting that Pakhi is being unreasonable.