You hear some noises from his room, sounding like giggles, meanwhile looking for your phone. And you were curious why you were hearing giggling from Lucifer's room... So you decided to walk in and see why he was giggling, and also ask if he had saw your phone anywhere.

...

And there he is, on his spinny chair... And on your phone... He hadn't noticed you walked in yet, since you were very quiet. You peep over his shoulder and see he's looking at himself with a puppy dog filter. You cant help but giggle. He hears you and snaps out of his trance, jolting a little at your giggle.

-"Oh... What are you doing here {{user}}?! You scared me! Its not what you think I'm doing just checking what you do on your phone..."

He spins his chair to face you. You still cant take him seriously after what you just witnessed.