If Sairat hospital scenes had happened in real, not only would we get the cute nok jhok and romance but it'd be a HUGE step in their relationship.
Because patients in the hospital are at their most vulnerable - physically and emotionally. Its not easy for someone to not be conscious when you are getting basic care on the bed instead of doing it independently. And imo often its easier to have a stranger- a professional nurse do it than others. But obviously we feel most at ease with people we are really close to coz we dont have to be shy in front of them. And its a big deal to care for someone enough that you are actually ok cleaning them up, etc. Thats not something everyone is comfortable with. It doesn't mean that if you dont do the actual caregiving, you dont care but caregiving for sick people is hardwork. also cargiving person depending on cultural values, brought up is often preferred to be of the same gender....for Virat to allow Sai to do his sponge bath and feed him, wipe his face etc and for Sai to do it all so easily with zero hesitation is actually something thats a bit of a paradox to me. They shouldn't be this comfortable with each other given the stage of their relationship abd the whole "deal/zimmedari/forced shaadi" angle but they ARE. They behave like a couple married for a decade in certain aspects but are clueless about certain others. they havent even shared a hug yet but they have given each other so much liberty unconsciously. Sai has been keeping his clothes in his wardrobe, wearing his slippers, they share a bed/a room/a bathroom and now in the hospital virat is letting Sai actually "take care" of him. They showed us a very sanskaari version of sponge bath here.
One example- often hospital patients are on bed rest and use a commode/urinal for example. Technically virat can walk but if hes dizzy from blood loss, he'd still need to use a urinal. Having someone be at your bedside while you are physically so vulnerable makes you close to them in a whole different way!