(Edited)
You know I was planning on making this more fluff like but then I remembered Sawamura sleeps on the top bunk
Sawamura enters his empty dorm room with a sad look on his face
He didn't like it, and he knows it's stupid, but he just can't help feeling jealous whenever he sees you and Furuya together, so many negative thoughts just run through his head. He trusts you with all his heart, but there's just a voice at the back of his head that always points out how you and Furuya just look so much better and from there it just goes spiraling down
He lay on his bed with his face on his pillow, gripping the sides so tightly that he was surprised it hadn't ripped. He wants to remove those stupid images in his brain, he wants those doubts to vanish
"Eijun?" You knock on the door and poke your head to check on him, "Everything okay, baby?" You ask, walking towards the bunk bed and looking up at him
"I'm fine." His voice was muffled since his face was hidden by the pillow
"You sure?"
"Yes..." His voice cracks
"No, you're not." You frown, looking over his bunk bed, "Come on talk to me, what happened?" You ask, trying to make him face you
He finally turns his head and you see tears brimming at the corner of his eyes, "WAH (FIRST NAME)-CHAN I'M SO SORRY!" He cries out, wiping the stray tears that fall from his eyes
"Wait—what's going on? Did you do anything?" You ask in confusion as he continues to sniff
"I tried stopping it 'cause I know it isn't good! But whenever I see you and Furuya I can't help but feel..." He trail off
"You get jealous?" You suggest as he nods, avoiding your eyes
"I can't help but think that you look better with him and that maybe you'll leave me for him and—"
Your eyes soften at what he said, you never knew he felt that way, "Eijun, look at me." You tell him but he just looks away
"Come on Eijun," You continue to ask him
Finally, his eyes meet yours as you reach out to caress his cheeks, "Eijun, I'm sorry I didn't notice it sooner, if you ever feel that way again make sure to tell me, alright?" You ask him
"Don't apologize! (First name)-chan didn't do anything wrong! I was the one who kept on thinking all those stuff and—"
"That's normal, isn't it? I mean, I would be lying if I said I never got jealous whenever somebody gets too close to you." You shrug as he looks at you
"You get jealous when people do that?"
"Course I do!" You pat his head, "So stop apologizing okay? And next time if you ever feel like this again, tell me so I can make you feel better." You smile at him reassuringly as he rubs his nose
"Then...do you want to join me here and cuddle?" He asks shyly as you chuckle
"Of course, sweetheart." You couldn't contain your smile at the sight of Sawamura beaming at what you called him
Once you finally climbed the bunk bed, you pulled him into your arms, with you two facing each other while you gently stroked his hair
"(First name)-chan?" Sawamura mumbles, looking up at you as you hum and stare at him
"Yes?"
"I love you." He grins, and you swear you feel your heart burst at how bright it was
"I love you too Eijun." You kiss his forehead as he snuggles closer to you