We all know about the love of Lord Krishna and Radha Rani. Many stories related to them are popular. Even today the tales of Radha-Krishna's love are sung in the Braj region. 

But we also know that even after falling in love, Shri Krishna and Radha could not get married. The reason for all this was a curse given to them. 

According to mythology, once Shri Krishna was roaming around with a gopi named Virja in the absence of Radha. When Radha saw this, she got very angry and insulted Virja. Radha also cursed Virja to suffer on earth as a poor Brahmin. 

pc: HerZindagi

Shri Krishna's friend Sudama was also watching all this. He did not like Radha's behavior. He tried to explain a lot to Radha but Radha did not understand. He also cursed Sudama to be born in a demon clan. 

PC: chowk

After this, Sudama also cursed Radha that despite loving Lord Krishna, she always had to suffer separation from him. According to mythology, it was because of this curse of Sudama that Krishna and Radha had to suffer separation.