They call it’s other unnie 언니|Some people call them '형(Big brother)', and others may have different names. sweetheart(자기), cutiepie(이쁜이, 귀요미), and Etc. I'm Hetero, but I had a chance to talk to the Homo-Sexual people, they called each other to '~씨'(Mr./Mrs). And Here something Interesting fact, In my early days, 'Unnie(언니)' was socially allowed expression that a.