My Lover Is a Demon {Sebastian x Reader}

Childhood Rivals and a Confession

You didn't fall asleep last night, instead you were thinking about Sebastian and when he left you. You were trying to remember what happened when he left. 'Did I make new friends?' You thought to yourself. "Lady (y/n), may I come in?" It was Mey-Rin's voice. You got up and stretched. "Yes, come in." Mey-Rin came in with some tea and bread. "The young master is out with lady Elizabeth, so there is no business discussions today. The young master sends his apologies." You smiled and ate some bread and washed it down with water. "It's alright..did Sebastian go with him?" You asked but not sounding too concern. Mey-Rin shook her head. You sighed happily. "I shall be going now, if you need anything just call one of the servants." She said and left the room, closing the door behind her. You got up and picked out a dress. "Time to explore this mansion!" You said to yourself. The door opened and Sebastian entered. "H-hey! What are you doing!?" You felt yourself blush. "My apologies lady (y/n), but I wanted to take you on a tour around the mansion." He smiled and you swore you almost fainted because that smile. "Y-you could have knock!" You threw a pillow at him and he threw it back right in your face. You giggled. "Let's go my lady~" He purred and he picked you up bridal style. You wrapped your arms around him and blushed lightly. "Lets go!" You said and off you two went, exploring the mansion.
After a while of exploring you made it to the garden. "Here." Sebastian handed you a black rose. You felt yourself smile. "Thank you." He hardly heard you but then something shook the ground. "Woof!!" Some person..wait a naked person was coming near you! The person leap on you, sending you to the ground, and started to lick your neck. "Pluto get off!" Sebastian demanded but that didn't work because Pluto licked even lower. You moaned softly. Then you felt lighter and stopped moaning. "Pluto that's enough!" Sebastian was mad and grabbed Pluto off of you. Pluto whimpered and wined but Sebastian just stared at him. "It's ok Sebastian. He is rather cute.." You said and petted Pluto on the head. He licked your cheek. "Go on boy go play." You said and Pluto did as told. "Sebastian!!" The trio called, Mey-Rin, Finny, and Baldroy. They came running to him. "There a letter for the young master!" Sebastian grabbed it and read it throughly. "It seems that the young master had been invited at the Tracny's house." Everyone cheered but you. "Can we please go!?" They asked in unison. Sebastian nodded at smiled. "That is of course if lady (y/n) goes as well. After all she is our guest." You were in shock. "B-but I don't have a costume." Sebastian took your hand and said "Don't worry I'll have Mey-Rin make you one." You sighed and Mey-Rin took you and went to another to make you a costume. When you entered you saw Sebastian whisper something in Mey-Rin's ear. You wonder what he said but brushed it off. "Alright let's get you measured and I'll make your costume." You nodded and waited.
~At the Trancy's House~
You couldn't believe it! 'Damn that Sebastian! He would! He hasn't change a bit..he still has a love of cats I see.' You thought to yourself. And why did you think this? Well because I certain demon butler ordered Mey-Rin to make you a cat costume. So there you were at the Trancy's door waiting the doors to open in a cat costume. You had cat ears, a tail with a bow at the end, and you had a short skirt on but of course with some fish nets. Sebastian came close to you and the only thing he was wearing was a mask. "My my~ lady (y/n) you do look rather fine today." He whispered in your ear making you shiver. You whispered back, "Don't call me that...call me by my name alone or maybe even call me that cute nickname you gave me when we're children." Sebastian smiled. "Alright then...kitten~." He smirked and nearly purred. You felt yourself blush and then someone opened the doors. "Holy shit! Claude!?" Your voice was heard. Ciel looked at you and so did Sebastian. Claude looked at you with no expression but you could see happiness in his eyes. "Hello everyone. My highness would be out here in a second so please come in." He said. Everyone entered and you swore you saw Sebastian and Claude glare at each other.
~Random Flashback~
"Sebastian where are you!?" You voice echoed like a broken record. Tears were streaming down your face. You fell and cried more. "Sebastian!" Your chest hurt. 'Where is the one that called me Kitten? Where is the boy I love?' You asked yourself. "Excuse me? Why are you crying?" A boy asked. He had glasses that covered his red eyes and his hair was almost purple. "Why is a precious rose like you crying?" He asked again. "S-some important left me.." You whispered. He shook his head and points at your knee. "You're hurt." He bend down near you and lightly licked the blood of your knee. "Your blood..it's really good~" he said his voice husky. Heat came to your cheeks. "I'm Claude. What might your name be?" You smiled slightly and said, "My name is (y/n)." Claude smiled. "Whoever left you is an idiot! Why would someone leave a perfect rose behind." He said. "For now on you are my precious flower." You couldn't help but giggle. This kinda remind you of when Sebastin gave you the nickname "Kitten".
~Flashback in a Flashback~
Before Sebastaian left he gave you a nickanme. You found him in an alley with a cat. "Sebby why do you have a cat?" You asked him. He smiled and squeezed the cat's paw. "Becuase, my dear, cats are so cute and soft like you." This caused you to blush. "S-stupid.." you whispered. "Kitten come here" Sebastain said. "Who in the hell is Kitten?!' You asked. Sebastain couldnt help but chuckle. "Why its you of course." You blushes even more but went near Sebastian. "Idiot.." You said and smiled.
~Back to the Present~
You met Alios Trancy and you thought he was a selfish brat. Unfortunately Sebastian wasn't able to dance with you but Claude was. He grabbed your hand and you two started to dance. "So how have you been my beautiful rose?" He asked. "Don't call me that!" You yelled. "Why not..you're mine after all." You couldn't help but blush and lucky for you Sebastian took you away. "Hello kitten~" he purred. You blush deepened. "I going to give you a treat tonight if you're good little girl~" he smirked. "W-what!?" Just when you said that Claude took you away. It went like that for about an hour. Until finally you were stuck with Sebastian. You danced and it almost felt like it was just you and him. "Sebastian..I love you.." He smiled and whispered in your ear. "We're going to have sex tonight." You blushed dark red. "W-why would you say that!?" He chuckled. "Because long ago I said if I fell in love with you.. I would have sex with you." You nodded. "S-so you're in love with me?" Sebastian blushed. 'He's blushing!' You thought. Sebastian nodded and said "My dear (y/n) I love you and tonight we shall have the dirtiest sex and you as my prime victim ."