Well I guess I should explain a little about the fanfic.

Key is a Fallen Angel you can say and he's in love with Jonghyun who knows what he is but they can't be in love, it's forbidden for fallen angels to be in love and Jonghyun at the end is saying he doesn't regret all the trouble he's been through to love Kibum and he never will... At the end the world ended and all the people died but remember how key said "If the world ended would you regret it?" Jonghyun says no because he didn't regret it because he met Kibum who made his terrible hard life worth something. AHHH I'M A Y AUTHOR I'M SORRY IT WAS SO CONFUSING

Does that make sense? :)