“Is the love given to you by your fans not enough?” read an electronic billboard placed outside a K Pop star’s agency’s headquarters. “Why did you choose to betray the fans?” Karina’s offense was having a boyfriend, for which she has now offered a deep apology. One of four women in the group Aespa, Karina recently confirmed that she’s dating actor Lee Jae-Wook. “I apologize for surprising you greatly,” the 23-year-old singer, whose real name is Yu Ji-min, wrote to her fans on Instagram, the BBC reports. Messages from fans, including the electronic sign, had demanded an apology and suggested Ka…