When you say "I love you"

You once said it while he was writing something. He just stared at you before nervously fixing his suit, asking why you would say such a thing out of nowhere. When you shrugged and said because it's true, he will get up and say he has to go before hurrying out the room, trying his best to hide his blush. Diavolo was very confused when he read the letter and it suddenly had I love you written at the end. Lucifer apologized many times for it, nervously explaining he thought he said it out loud to you in reply but it seems he wrote it down instead because he was too shy to say it out loud to you.

He stared, his brain still trying to process what you just said. When he finally understood it, he let out a weird noise you never heard him make before as he looked around, as if searching for an exit, stuttering out that's nice of you and he knows that and he's cool so obviously you love him. When you asked him if he isn't gonna say it back, he let out a groan because he wanted to say it, but he found it so awkward/weird to such say a thing. He stayed silent for a long time before he covered his face to hide his blush, whispering he also loves you. When you hugged him, he let out an embarrassed sound, stuttering out he doesn't need a hug while wrapping his arms around you.

He almost dropped his figurines, nervously stuttering out how you shouldn't say such things as if they're normal while making sure the figurine is okay with trembling hands, mostly checking on the figurine to distract himself. When you tell him the other person normally says it back, he will blush and frown, saying it's an embarrassing thing to say. When you shrug and leave, he will hit his forehead with the figurine, groaning out he's an idiot for not saying it back. Later while you were both playing, he send it via chat, messaging he knows it's not the same as in person, but it's at least a start so just wait till he's mentally prepared enough to say it back.

He will let out a nervous chuckle, unsure how to react to this before he nod, saying he feels the same while giving your shoulder a very awkward pat because he has no clue what else to do. When you tell him to say it back, his face will turn red as he whispers he also loves you.

He will let out a gasp before happily saying he also loves you and giving you a hug, saying he's so happy to hear that before giving you a kiss. He will take a selfie then post it on Devilgram, bragging about how good his relationship is and that you said I love you.

He will give you a goofy grin, picking you up while hurriedly emptying his mouth so he can reply with I love you as well before cuddling you. He will refuse to put you down for the next hour, happy you said such kind words, he will cuddle you while eating his snack.

He stared, having just woken up before his eyes widen and a blush grew over his face. He stuttered out to not say such things when he just woke up before he sat up, hurriedly wiping his mouth to make sure there isn't any drool before he got serious, replying in a serious tone he also loves you. When you laughed, he felt embarrassed but tried his best not to show it, saying not to just say such things out of nowhere.