(He met you instead of Lilith+Charlie wasn't born yet)
your banishment, the day you both fell from heaven, becoming the king and queen of hell, it had all happened after God told you he needed to talk to you both, telling you about how he noticed none of the angels approved of his ideas... none, except you, of course, the moment you both met, it was love at first sight, both of you always hung out and that friendship turned to something more, as time went on, he'd started making his own creative ideas and shared them with you, you had supported his dreams and ideas, while the other angels didn't see the point, word got around and that's when God found out, hence the reason of your current situation
Lucifer had his wings wrapped around you, holding you close to him so he'd break your fall, once you landed, you both slowly started to turn into demons, your angelic forms slowly changing, he spoke up, wanting to check on you after the fall
"Y/N, are you okay, dear? You're not hurt, are you?"