'What did you just call me?'
Harry blinked slowly, glancing up from his hands to meet his professor's icy gaze. He was in Snape's office, trying to explain why he had been on the stairs leading down to the dungeons at three in the morning with tears streaming down his face. Snape had immediately dragged him to his office and started questioning him. Ever since Harry had defeated Voldemort, the two men had gotten considerably closer, so Snape hadn't blasted him with a detention and docked points. Harry had hesitantly explained how Ron and Hermione were practically ignoring him, and when Snape had rolled his eyes, Harry had accidentally called him Severus when reprimanding him.
'Uh, I called you... Severus?' Harry fidgeted as he talked, suddenly nervous. He had totally forgotten Hermione and Ron.
'And who said we were on first name basis?' Snape arched an elegant eyebrow, pushing himself off the wall to circle Harry's stiff form.
'Uhm... I did?' Harry bit his lower lip hard, feeling heat rise to his cheeks as Snape moved closer. 'I mean, we've already made out, right? Surely we're on first name basis?'
Snape paused in his pursuit, frowning. 'Fine, Potter, but only in private.'
Harry grinned and turned to face him, pressing their bodies flush together and burying his face in Snape's neck. He felt the subtle shiver going down the older wizard's spine and nipped at the skin, feeling the man jerk in surprise. 'We're alone now... Severus.'
No answer, only heavy breathing, so Harry tried again. He swirled his tongue over the spot he had bitten and started to suck ever so slowly. He felt Snape reach down to shove off Harry's robe, but Harry grabbed his hands and shook his head. 'Not until you say my name.'
'...Potter.' Snape made to move away, but Harry held him in place and continued to lick and suck his neck. Snape relaxed slightly, and Harry grinned. 'Not my last name, Severus. My first name.'
Snape groaned and pushed Harry away. 'Fine. Harry. Are you happy now?'
'Very,' Harry laughed, and allowed Snape to grab his robes and push them off.
Harry made Snape scream out his name several times that night.