Your ear cracks when you swallow because a tiny tube opens to balance pressure. It’s normal, it’s harmless, and it’s kind of cool.
Next time you hear it, give a little smile. Your Eustachian tube just did its daily workout. You’ve got a perfectly weird, wonderful, working ear.
And if someone looks at you funny when you crack? Just shrug and say, “My ear is just saying hi.” They’ll probably check theirs on the next swallow.