7 incredible scientific things that happen to Your Body When You Kiss Someone

Since a first kiss triggers your sympathetic nervous system, aka that fight-or-flight response, your pupils will dilate, too. While it sounds strange, the pupils seriously widen whenever we feel intense ....attraction, so if you’re kissing someone you are heavily digging, and want to know if they’re feeling the same way, check to see if their eyes are dilated, too. Fun fact: this also might be one of the reasons we close our eyes when we kiss, because when our pupils are so open, it makes us susceptible to light sensitivity.