Sorry it might be slightly out of character for Nowaki but I was just thinking back to the episode where he was going crazy chasing after Hiroki in the school and almost punching Miyagi because it was stopping him from being with one and only.

"It's over!"

Hiroki spat suddenly at the tall male in front of him and hung his head to the ground. He stood clenching every muscle in his fragile body, hoping and begging for the reaction of his lover to be a simple 'okay' and then for him to slowly wonder out for a few hours. Pain grew and grew as the awkward silence lasted longer Hiroki couldn't look at Nowaki's face but he imagined it to be very shocked. The shorter of the two swallowed leaving his mouth dry and speechless, while the taller male held his large hand to his face hiding the feelings that spread across it. Hiroki's eyes drifted up to the hand grasping the student's face while guilt spread across his. Hiroki's eyes widened, his lips trembled, tears built up around his eyes as he kept himself from pulling Nowaki into his arms and whispering 'not really'.
Nowaki sniffed loudly breaking the silence; he slid his palm down revealing a depressing wet face. Hiroki felt disgusted, he was hoping his lover would burst out any minute now and refuse it.

Yet nothing but more silence.

"I love you" Nowaki pushed "I love you" he repeated.

"Don't you love me?" "Because I love you" he continued.

Hiroki opened his mouth yet nothing came out, he was left to stare at Nowaki open mouthed and a tear running down his cheek. The taller of the two lifted his hand and took his lovers face into his palm, and watched how his uke shut his eyes and closed his mouth. Nowaki knew he had to change Hiroki's mind fast, he couldn't feel his body for a while he just had to go straight in there. Keeping this in thought the student gripped his lover's wrist with his free hand and heaved Hiroki against their apartment wall.
Nowaki swallowed and faced the professor moving in for a kiss.

'Bastard, that hurt!' Hiroki yelled before being bitten on his bottom lip playfully by a slightly scary Nowaki. Spinning the brunette round to face the wall and sliding his boxers down to his knees Nowaki now had both wrists held tight above Hiroki's head.

"Nowaki what are you-" Hiroki let out a loud moan as a hand rubbed one of his balls causing an erection. Nowaki slid his finger up and round to the tip of his lover's penis and pushed it into the open hole. Nowaki became hard as cold juice squirted onto his hot palm; he pushed his finger down further causing Hiroki to struggle. Nowaki became aware of his heavy breathing and gently pulled his wet finger back out his uke's erection. Hiroki rested his body as Nowaki released his weakened lover who collapsed to the floor immediately. The black haired male stepped back shaking his head at Hiroki half naked and crying on the carpet. His eyes flickered to the semen on his left hand making Nowaki feel scared of himself.

"No... I..."

Hiroki cried loudly, sniffing and hyperventilating at the same time. He lifted his fist and slammed it onto the wall.
"I'm so-so-sorry" Hiroki whispered to himself loudly. He thumped the wall constantly opening a wound on his knuckles; drips of blood began to smear the walls.

"WHO" thump "ARE" thump "YOU!" thump. Hiroki crashed his head into the solid wall and pushed it down the burning his nose and forehead. Nowaki's rage built up he wanted to die. All Hiro-san wanted was for our cold relationship to end for good, for the past months the two of us hadn't spoke. I hadn't known what to say, and for a long time all I'd thought about was Hiro-san and that if anyone else was to hurt him I would kill them... I've hurt him. Must I die? Nowaki thought.
He staggered over to the couch where the two of them had touch many times, grabbed his bag and flung it over his shoulder before taking one last look at Hiroki, shaking his head and leaving their apartment for good.

The door slammed leaving Hiroki to cry on his own.

"Nowaki, I love you. I love you so much, GOD FUCKING DAMN IT I LOVE YOU!' Hiroki moaned hoping his lover would race back. "It's my entire fault" he whispered "If I hadn't been seduced-" Hiroki stopped he didn't want to say it.

"I just wish I didn't do anything, and I wouldn't have to end it with my Nowaki, and miss that dazzling smile."