Her obsession (Giyuu x reader)

19.

Giyuu was waiting for you laying on his desk.
You didn't even greet him, you just stood there with your arms crossed waiting for an explanation.

"So uh..."His right arm was scratching his scalp, he was clearly nervous.
"First of all I wanted to tell you that I'm sorry for leaving like a thief in the night after we... you know. It is something unforgivable and I understand if you're mad at me."

Your arms were still crossed, was it all he had to say to you?
You just rolled your eyes, but then he came closer to you.

"I'm sorry Y/n... I really am." He said kissing your hand.
"What about your little girlfriend? Aren't you sorry for cheating on her?" You were speaking with great venom.

"Don't bring her into this discussion, it's about us that I'm talking about."
"Just admit that you took advantage of me knowing I have a crush on you!" You were trying to keep your voice low so that no one could hear you from outside.
"Fuck, no... Is that what you think of me Y/n?" He narrowed his eyes, he couldn't believe what he has just heard.

You didn't answer him, you didn't know what to think of him, so you just looked away.

"I know you went out with Douma last Friday, that's the main reason why I called you in." He confessed.
"So what?"
He grabbed both of your wrists with one hand and pinned them behind your back.
"I explicitly told you to stay away from him, didn't I?" He was dangerously near to your face.

"Did you have sex with him?" He clenched his jaw.
"That's none of your business, Mr. Tomioka." You said coldly ignoring the fact that he was basically towering you and someone could enter any moment and see you two like that.

"Oh but it is my business since a dear student of mine is hanging around with a criminal, don't you think?" He caressed your face with his free hand, his tone what somewhat mocking.
You flinched at his touch. "Criminal?"
"We don't have much proofs but he works for Muzan, do I need to tell you more or your little brain can guess what that means on its own?" He teased you, and with that said he let go of you.

Muzan Kibutsuji was an ex student of the Kimetsu Academy, he was well known for getting into troubles and having shady business. You were just a freshman when he graduated, so you didn't remember him that much. He would occasionally glare at you and that was enough to scare you and walk with your head lowered.

"You know I don't like when my students don't listen to me." He said while sitting on his chair.
"Come here." He patted his lap, meaning you had to sit there.

And so you did. Your heart started racing.

"You know I hate students that talk back and misbehave right?" He said while placing you over his knees in a position where he could spank your ass.

He started lifting your uniform skirt before speaking again. "I asked you a question." And then he spanked you.
The spanking got you by surprise. "Y-yes."
"Then why are you acting like that? It's like you're doing it on purpose trying to piss me off." Another slap.

"Aren't you going to say anything?" Each time he spoke the spank got louder.
"I-I'm sorry... I won't do it again, p-please stop." You said while grabbing onto his hand for emotional support.

"It's too late to say sorry. You got in a huge trouble and unfortunately you may come to an use. My higher-ups discovered your relationship with Douma and want you to keep dating him in order to discover what Muzan is plotting." This time he didn't slap your ass since it was red and you couldn't bear the pain anymore.

"Higher-ups? Are you a spy or something?" You said trying to get up from your position but he stopped you from doing so.
"I guess you could say that. I tried to warn you about staying away from him, and the thought that now you'll have to keep seeing him makes me see red." He slapped you again, this time in angry way which made you whimper in pain.

"That's what you get for not listening to me, you're too young to get in this kind of trouble y/n." He finally stopped spanking you and covered your behind with your skirt.
"What if I don't help you out?"
"I'll have you get arrested when we discover the truth about Muzan." He simply say.

"What? You can't do that!!" You got up from your position and now you were on your knees beside him, like a dog.
"And who do you think you are to say to me what I can and can't do? Just stick to your job and be useful." He coldly said.

"Tsk. What do I need to do exactly?" You scoffed and crossed your arms in annoyance.
"For now try to discover what his real job is. The Kizuki's is posing as a software company, but we are afraid that Muzan is involved with the mafia. A bodyguard will be assigned to you whenever you go out with Douma, just in case he tries to harm you.
I don't like him but he's the only one that is available at the moment. His name is Sanemi Shinazukawa, you'll be meeting him outside of school in about 10 minutes. Try to not fuck him too." He said the last sentence with resentment.

You were overwhelmed by all those informations. "Why can't you be my bodyguard?"
"Do I really have to answer your dumb question, y/n?" He was annoyed.

"I want you to text me whenever you sense something suspicious in Douma's behavior. Keep in mind that you'll be texting me exclusively for this purpose, I won't tolerate any of your shit." You didn't understand why he was so cold towards you after he basically took your virginity.

"Do you regret it?" You said in a low tone, not clarifying what you were talking about but you knew he understood.
He didn't answer back.
You were about to leave but he grabbed your wrist and kissed you.

You were doing it again, kissing your professor knowing he has a girlfriend waiting for him at home.

But you didn't care, you are selfish when it comes to him.

He put you on his desk and placed himself in between your legs, without breaking the kiss.

He unbuttoned your school uniform and cupped your breast with a hand while sucking on the other one and with his free hand he started teasing your clit through the panties.

You were trying your best to not moan since you both could get in big trouble, but it became harder when he inserted two fingers inside of you.

"I bet you thought of me the whole time while fucking him." He whispered in your ear.