This is unbetad and it's almost 4 in the morning. Disregard all spelling mistakes please.
It was one word that changed everything.
"Daddy." Kurt whispered, his lips barely moving as Blaine pounded harder into him. Blaine's thrusts stopped for a half a second, as he looked down at Kurt with wide eyes.
"Kurt, Kurt, what did you just say?" Kurt's face reddened even more than it already was, and his half lidded eyes shot open.
"I didn't say… I didn't say anything." His voice was quiet and unnerving.
"You called me daddy, Kurt." Blaine couldn't believe it. Kurt had a kink. He'd been so plain with sex before. He liked the occasional dirty talk and frottage, like every other teenage boy. Even after Blaine confessed his thing for crying (one of the first reasons why Blaine had been instantly physically attracted to Kurt on the day they first met, even if he couldn't realize why then), Kurt hadn't confessed to liking something outside of the norm. He'd purse his lips every time Blaine brought it up and say What's so wrong with being normal, Blaine? and drop or change the subject.
And now, in the throws of passion, amazing sex if Blaine might say so himself, Kurt called Blaine daddy.
Kurt's cheeks were still bright red after Blaine pulled out and sat on his thighs and he began to do the squirming arm thing he did whenever he got nervous. Blaine held his arms down to the bed.
"It's fine, Kurt. I'm fine with that. Really."
"I thought maybe… with your problems right now at home…" Kurt trailed off, looking pointedly everywhere else besides Blaine's eyes. It was common knowledge that Richard Anderson wasn't the most supportive dad around, especially with Blaine's whole 'gay thing', as he liked to call it. He'd push around the subject, calling it a 'phase' and 'something he'd grow out of'. He'd been nothing but kind to Kurt, he wasn't an indecent man of course, but he'd reject the term boyfriend and date and prom and things like that, replacing them with words like friend and xbox and sports and Harvard.
Blaine thought over the phrase daddy for a second, his eyes skimming over Kurt's head and lazily focusing on his headboard. Daddy. It gave him a strong sense of respect and pressure. But he also felt strangely happy. Like the term let him let go of some of the problems with his own father. He'd never called him daddy, anyway, even as a child. It was always father or sir or sometimes occasionally dad, when he was fixing cars with him or playing catch. It was never daddy. Daddy was a name left for someone who was really loved, who was really cared about, who made and kept promises and who was always there.
"I like it, Kurt. More than you probably think." Blaine whispered, leaning down and kissing Kurt.
"Really?" Kurt whispered back, excitement leaking through in his voice.
"Really." Blaine said back, his voice gravelly and low as he lowered himself into Kurt again with more fervor and passion than before.