I went to a wedding yesterday and they played "Oppa Gangnam Style." I was literally the one person screaming the lyrics, I actually got a funny look from my friend, David.
Anyway, I didn't get asked why I listened to Kpop, however I was waiting for the question to pop up any minute. Earlier today I remembered that I had two downloads that would help me answer in such a way that other people would understand. Telling them about the looks, the rythm, or MVs would not work because it would take some time for them to understand. These are fast and easy ways to help people understand why we love Kpop.
Bring up the person's favorite foreign band that does not live in the U.S. (or country you live in). Sure, the language is not a barrier in this case. However, the whole point is that they are from another country therefore unreachable.
If they tell you, "but you cannot even understand what they say". Just tell them, "The Internet is a beautiful creation that allows me to search for the English lyrics."
If they still don't understand, which they should have by this point, then move on to the next block to find out. :P
Ask them food related questions! Everyone can relate to food and I don't know anyone that does not eat food from another country.
The picture already points out a good point, "Why do non Mexicans eat tacos?"
I don't even think you would have to explain any further.