It's understandable to want to keep certain feelings private, but it's also important to recognize the way that the body communicates feelings that the mind is still trying to process. It's possible that your eyes were sending a signal of interest, but it's also possible that they were simply reflecting the admiration you feel for your acquaintance. Regardless, it's wrong that our eyes are “a bunch of little snitches” - they can't be controlled the same way we can control our words.
