You don't really know what comes over you but you immediately move towards it and start talking to it, politely asking the snake to be calm and move away. You have spoken with a snake before and it was, in fact, really friendly, so why not try?
You assumed everybody can do it here, but once the snake curled on the floor (napping?) you looked at your friends, and those around you, and pure shock started back at you. Even Ron looked at Harry as if seeing him for the first time.
It was explained to you later that you were actually speaking Parseltongue, a snake language that is incredibly rare! It has an unfortunate reputation of being a trait of dark wizards, although you tried explaining how innocent and actually kind of cool this skill is! You did notice many side-ways looks after you all were dismissed, while the Great Hall was being prepared for dinner.
Hermione suggest heading back to the dorm until dinner is ready, to avoid all the curious stares, and you do not object.
You were making your case as to why you should stay and not go down for dinner (you had just about enough of people staring and whispering!) but both of your best friends literally grabbed you by your sleeves and pulled you after them. You do need to eat after all.