This was a post from imagineyourotp on tumblr, which I unfortunately haven't saved, but, you know, read it and you'll figure it out.

Basically, Kurt and Blaine waking up hungover in Rachel's bed… with Rachel in it.

Uh-Oh

Blaine opens his eyes, and shuts them quickly again. His head, oh god. It feels like someone with hammers for legs is tap dancing on it. Or just like he has been run over by a truck.

Someone nudges his shoulder. He groans.

"B," a familiar voice whispers. "Wake up."

He groans again; Kurt pinches his waist and he startles, opening his eyes quickly. The sunlight that hits them, although it's quite dim, is way too much and he has to try very hard not to just roll over and shove his face into a pillow.

Kurt's expression is terrified when he manages to focus it. "Be quiet, don't wake her up. Let's just leave."

"Wake up who-" Blaine looks around, and then jumps. "Shit!" he mutters.

On his other side is a very asleep and very naked Rachel Berry. He never wanted to see Rachel Berry naked. Much less in the same bed as him.

Okay, maybe he did, for like two minutes on his junior year in high school, but that doesn't count! He's engaged now and he's sure of his sexuality and he… He thinks he can see her v- he's not even thinking its name. Oh god. Oh god.

"How much did we drink?"

Kurt whimpers, and pulls at his hand. "Let's get out of here, please, I can't look away and I don't want to look anymore."

They roll out of bed carefully, forgetting about clothes and running-tiptoeing their way out of Rachel's bedroom and into theirs. On the way there, they spot Santana sleeping on the couch, and thank all that's holy that she's not awake.

In their room, they land on the bed together and huff out in relief.

"That was terrifying," Kurt says.

"Do you think we just slept with her, or like… slept with her?"

Kurt buries his face Blaine's shoulder. "We were all naked, Blaine- we still are, fuck- we weren't playing Monopoly."

"I-"

"Oh my god!" a screech echoes through the house.

"Berry, shut you piehole! I'm asleep!" is the reply from the living room.

Kurt swallows. "Do you think she's seen our clothes scattered there yet?"

"Holy-!"

"She just did," says Blaine, his headache growing stronger, and he's not sure if it's because of the hangover to because of thinking about sex with Rachel.

"Let's get dressed and go out for breakfast to escape."

"You have the best ideas."

"Why is Lady Hummel's clothes- oh, damn."

They look at each other, eyes wide, and run to the closet.