Past:

“Okay! I accept the fact… It’s okay if you’re not in love with me anymore, I will go away from your life Kai! Go live happily without me whining or nagging to you. Thank you for all of these happiness that you had previously gave to me.” Krystal said while wiping her tears.

Present:

"Don't do something you will regret later!" 

there they are.. living happily ever after together.