I too have noticed. From the initial episodes we have seen Virat holding her hand but from the time they reunited there's something else in the way he holds her hand. They look so comfortable specially Sai. And, when he held her hand tightly while blasting his baba that was in a different level altogether. Even Pakhi kept on looking with her bulging eyes. I think these small things will lead Sai to realise his love for her.