Sai and virat always bring out the worst and best in each other. They both have the ability to make or break each other. They've always been drawn towards each other.
With her he moves inward and can't stop himself from expressing how he's feeling and doesn't put restrictions on himself.
We say that we only get hurt by people we love. And we're only our TRUE SELVES with people who are close to us and with whom we've no fear of expressing.
That's why virat does express and behave all kinds with sai. With rights of doing so.
(not justifying what he did to sai, that's unforgivable without virat's true repent).
It's the pain that'll cause him to react angrily, as if in a way he wants to say 'how dare you stay away from me for so many years? How dare you take away my rights of spending so many years with you and being together with you? How dare you take away so many beautiful years of my life and the things we could've done together?'
The immediate anger reaction is because of these thoughts.
People guessed that he's mad because he had to marry pakhi forcefully. Yes, he'll be angry about that but that reaction wasn't because of pakhi, because he isn't even in a state to think about her. He's only ant only thinking about how sai stayed away from him, he might even think that she FAKED HER DEATH.
AND, THE THOUGHT THAT SHE'S HERE DANCING AND ENJOYING HER LIFE AND DOING SO MANY THINGS, WHILE I'M BEING SAD, LIVING SADLY AND NOT EVEN ALIVE COMPLETELY.
SO, IT WAS JUST ME, WHO WAS LIVING WITH PAIN AND HURT FOR ALL THESE YEARS, THINKING SHE DIED. BUT, SHE'S HERE LIVING, ENJOYING, FAKING HER DEATH.
It's virat's nature. He gets angry in a second and cools down the next. But, here it won't be that easy.
Sai's physical pain is something that can melt him and make him cool down, right away. Tbh, sai's physical pain is the only thing, rn that'll make him forget all his pain and anger and shower all his love and pain in sai.
Cause, he forget all of his pain and everything when he senses that sai is in danger.
Except for Sada kidnapping track.
It was the hurt that came out in anger's form.