system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do the sides of your jaw hurt when taking the first bite of certain foods? (and only the first bite)
gpt
Whenever you eat something with a lot of flavor (especially sweet or sour) after not eating anything for a while, your salival glands on each side of your jaw begin to rapidly secrete salive to break down the enzymes in the food. Imagine it like a sleepy cop in the security room with all the screens showing footage from cameras. When he finally spots something, he falls out of his chair startled and calls security. Similarly, the spontaneous secretion of saliva makes your salival glands hurt or "cramp" up in a way.