Messing with the new kid at work

So there is this Korean guy that just started a few days ago at the restaurant that I work at and I love practicing my Korean on him.
Like, today my boss told me to call him 오빠 because he was born in 1990 and I was born in 1993. But I think it's really cute that girls use the word towards their boyfriends as well. So after she instructed me to call him 오빠, I said it in the cutest voice I would muster and I think I saw him blush. And because it's valentines day and I know he doesn't have a girlfriend, I decided to try a word I've always wanted to use. So, after my boss walked away I looked at him and said, "자기야" He blushed so red and me and the boss' daughter couldn't help but laugh so loud that we almost got sent home. Worth it.

haha,that is so funny story. He must be a very shy guy, but a good boy. Yes, we like to hear  the word,"  오빠" whatever the Korean men are old or not. haha.