Preston Burke was not a happy man.

He wasn't stupid. He could put two and two and two together. Sometimes not right away, but the solution would usually hit him after a few seconds.

Cristina had not slept at home that night. She'd been on-call. And yet Cristina had that post-coital happy look that she usually had the morning after they had amazing sex. Scratch that, after they had regular sex. Because seriously. He was Preston Burke. Even his regular sex was amazing. But right now, right at this moment when he had time off and he knew she did too, she was nowhere to be found.

He'd suffered through a long, silent elevator ride, too, with an angry, angry he-Shepherd to boot. Shepherd had been at the hospital all night, working on two different surgeries, with only a short break in between. From what he'd heard, though, the surgeries had been successful - and yet, he had that gloomy, brooding look on his face, like that time at the prom when Grey had shown up with another man for a date.

The final piece ofthe puzzle was a sheet of paper he found at the nurse's station, with the names and dates of the all-night on call shifts for the week. His eye caught on last night - Yang, C., O'Malley, G. and Grey, M. were the only names listed. As far as he knew, George was the only one who had scrubbed in on Shepherd's surgery...

...and suddenly, a crazy thought hit him.

"No they DIDN'T..." he muttered, as he headed for the on-call room. As he turned the knob, he heard a familiar moan, and he paused-

- Just rip the stitches, Burke -

-and there it was, in all its glory. Cristina pressed against the wall, Meredith Grey with those thin little fingers pressed inside her and her other arm holding Cristinas' above her head. Meredith's face was buried in the crook of Cristina's neck, and Cristina's head was thrown back,eyes closed, that sweet little grin on her face that Burke loved so much.

As he watched, Meredith pumped her fingers into and out of Cristina, thumb probably rolling against Cristina's clit, he realized, and Cristina looked like she was trying to climb the wall backwards, moaning and writhing as she rose higher and closer, moaning and hissing and it was too familiar, it was too bizarre. He had to say something right now.She had to know that he knew, RIGHT NOW, or else...

Cristina's eyes shot open, catching onto Burke's startled face and STARING STRAIGHT AT HIM as she orgasmed, her mouth open in a silent scream as Meredith thrust one last time. Her head lolled down and she collapsed into Meredith's arms, hair falling into her face.

Burke backed out of the room and shut the door.
He needed a moment.