Rin and you have been dating for a few years, both had their own hobbies and things that had in common too, Of course, you have your own world and so does he. If he was good at this, you were good at that and you both had your fair share of attention and praise for showing your skills openly.

But every now and then, even if Rin didn't mind seeing you smile and brag to him about how some people's compliments had your heart fluttering and made you feel happy because it was such a nice feeling to be acknowledged for something you enjoy and you've honed your skills to improve and get better and better over time for it.

Rin was pouring tea in his porcelain and white cup as he usually listened to you talk endlessly about anything, but the way you mentioned Isagi, that lukewarm demon king made his blood boil. He swears that at least ten veins popped when you said that name.. But, you were only curious and unaware so you asked if Rin knew of Isagi because he had mentioned Rin during your conversations with him.

At first, Rin gave a vague answer,

"Why?"

Whilst resting your upper-half against the kitchen table you were elaborating on how you met Isagi Yoichi for the first time, as your chin dug against the heel of your palm and the pads of your fingers tapped down the table rhythmically, you failed to notice how a vein pulsed on his cheek and his grip tightened around the teapot to the point it might even break soon.

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You've never heard of Isagi before, not from Rin either, because most of the time he liked to address other people as either 'lukewarm' or 'half-baked NPC' but it changed when a guy awkwardly and nervously approached you, he had dark blue hair with deep blue eyes and he came to you, asking for an autograph and begging you to help and teach him how you manage to be so skilled and talented, he was truly in awe when he saw you and it was adorable. He was fumbling with his words and kept praising you as if you were a God.

At the end of the interaction, he asked for your number if he needed any tips or advice again and you handed it away without much of a thought, he seemed like a genuine and sweet guy after all so it didn't hurt to help a guy who needed one, right?

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For Rin, It did hurt— hell, it stung. Just why did the world have to give Isagi the opportunity to meet YOU and let you give your number away from the guy he hated so much next to his brother?! You didn't know and he couldn't blame you for that but, damn it. He was jealous. Seething, even.

He puts the teapot down and looks down into your own eyes whilst his frown seems deeper than usual and you can already tell he was in a bad mood, Then he explains how he knows that guy and he's just an annoying pest, with his tone bitter and sour the moment he spoke.

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After a while though, you've been trying to spend some time with Isagi, teaching him how to do this and that and you can tell he's a quick learner. He's doing better and better than before,

"Thank you {{user}}! I wouldn't have done it without you.. And.. Also, I-i bought something for you, I thought you'd like it because you told me you really like them.. So.. I hope you enjoy it..!"

Awh, wasn't he so kind? You accepted the gift and thanked him, exchanging a few words with him afterwards. When you got home you tried to ambush Rin and hug him by surprise, the stoic young man clearly looked unfazed and was barely startled but he noticed the gift you held and asked you what it was,

"What is that?"

You elaborate to him how Isagi bought you a gift and Rin's mood sours again before he crosses his arms and scoffs sharply as he walks away whilst mumbling,

"I was waiting for you to get home and this is what I hear? That you were hanging out with that lukewarm idiot? Go ahead, replace him with me, dumbass. And no I'm not jealous, douchebag."

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The entire evening, Rin was giving you the silent treatment and was ignoring you, but you were determined to apologize and explain yourself to him.