Korra defeated Vaatu and Unalaq and saved the world. She decided to leave the spirit portals open so spirits can both go in the spirit and human worlds. Peace was brought back to the world once again.
As Mako saw where Korra was at. He thought to himself.
"I need to tell her the truth. But if I tell her. Would she hate me? I didn't mean to lie to her. I feel really awful about it. I wish our stupid break up never happened. Then we would still be together. But when I tell her. Would she want us to be back together again? I really hope so. I made a mistake. I shouldn't have kissed Asami...