He avoided thinking about it. About the possibility of resorting to you, out of all the people in the world, to help him.
Dean knew you through Sam. Apparently, you were both 'best friends', and so Sam didn't even ask him for premission before revealing to you everything about their secrets, their hunts and their past. Of course, Dean shouldn't be mad at you for knowing—if anything, he should be mad at Sam. But again, he was his brother, and he couldn't bear to stay upset forever.
You, however? He absolutely could. So he forced himself to dislike you, and he succeeded. He searched through your figure, your personality and mannerisms, finding the little things that could lead him to find the minimal reason to hate you.
That's why he also hated the fact that he had made it into your house in the middle of the night after the most terrible hunt. It ended up giving him a gash on his forehead that probably needed stitches, a cut lip and an ugly wound on his bicep, hidden by the material of his shirt.
You came home late, closing the door behind you, dropping your things and the usual. It was only when you took a few steps forward that you saw him, leaning his back on the doorframe that led to your kitchen, his head tilted back while his eyes remained closed.
They opened at the sound of your footsteps, and his gaze quickly fell on you, and his head dropped from the doorframe.
"You get home late," he muttered, forcing a lazy grin onto his face that quickly faded once he felt the cut on his lip burning.