In my opinion, Konglish goes both ways. Just as Koreans for many decades have adopted English words as their own unique means of expression, gyopos around the world have integrated Korean terms into their daily expressions.
Though we primarily speak to each other in English, Cyndi and I, for example, are prone to use certain Korean terms because it just rolls of the tongue more easily.
Here are some of our favorite Korean words, most of which do not have an exact English counterpart. I should note that our usage of these words may slightly depart from the dictionary definition. That's why I think of them as Konglish.
naesoong (내숭 )
Approx. meaning: To be coy
Salary Man: Sshindi, one shot!
-Cyndi takes a small sip from her soju glass-
Annalog: Cyndi is being so naesoong right now. She drinks a whole bottle of soju for breakfast.
bbijyeo (삐져 )
Approx. meaning: To be ticked off; miffed.
(1)Piggy is bbijyeo because you're sleeping on her pillow.
(2) The ajusshi had to skip sam-cha, before his wife gets bbijyeo.
byeollo (별로 )
Approx. meaning: shoddy; unimpressive; it sucks.
(1)Dang, that restaurant is so byeollo. I can't believe they charge man-won for that abomination they call "steak."
(2)Annalog: Cyndi, what did you think of that guy?
Approx. meaning: to do roughly/approximately; half-arsed.
(1)Cyndi: The recipe calls for 50 grams of butter. How much is that?
Annalog: I don't know... Just daechoong it.
(2) I made Cyndi some miyeok-gook for her birthday, but I just made it daechoong. I just used dashida and water.
(Neither Cyndi nor I really use this term, but I like the sound of it.)
Approx. meaning: to be mad irritated.
(1)Blech. That ajusshi... Jinjja jjajoogna.
It's really easy to make fun of the Engrish on Korean t-shirts or stationery, but I'm sure that if native speakers heard our usage of Korean terms, they'd have a laugh as well.
Even though their usage of English may sound hilarious to my ears, Koreans at least have a sense of humor about their Engrish.
See. Check out this pineapple ice bar. It's called the "I'm Pine" bar. It's a Konglish pun! I'm not sure if the makers of this confection were being ironic (especially given their default recitation of "I'm fine. How are you?") , but I like to think so.
The bar has a creamy strawberry exterior and an icy pineapple flavored interior. It's not as tasty as it sounds, but it's only 700won.