*This happens in season 6, Sam and Dean are on an easy case from Bobby*
Sam winced as the blade hit the floor, the metal tink against the tile floor sounding much louder than it actually was. Sam was trying not to wake Dean up. Sam was in the bathroom, Dean in bed sleeping. Sam picked the blade back up, his hands trembling. The faint pale lines zig-zagging across his wrists and arms. Sam thinks of all the times he let Dean down every time he couldn't save Dean. All those Tuesdays, watching Dean die everyday in every possible way. Sam was crying now, the tears slipping down his cheeks. He brought the blade to his wrist, he pushed the blade down, his mind begging for release, Sam dragged the blade across. Almost instantly a bright scarlet line formed, then it turned a deeper crimson as the blood beaded up and dripped down his arm. Sam then lost all control and began to slash at his arm over and over again. Over 15 scarlet lines appeared on his wrist. Sam sat there on the edge of the dirty bathtub, savoring the pain. That burning/tugging feeling brought him so much release. The cuts weren't too deep, so Sam hid his blade and reached for the first aid kit. Sam looked everywhere, making as little noise as possible, but he still couldn't find it. So he ripped off a long piece of the towel and wrapped it around his arm. Putting little pressure on it they stopped bleeding. Sam rolled his sleeves down, wincing as the rough fabric brushed against the fresh makes sure there is no evidence of cutting and went to bed. Emotionally and physically drained he drifted off to sleep pretty easily.
Dean woke up to the sun in his face. The motel curtains were open, which was weird. So Dean got up out of bed after rubbing his eyes, stretching and yawning. There was a note taped to the window it read:
Dean,
I went to the library to do some research on the Wendigo. I'll be home late so don't worry.
Sam
Dean was confused on why Sam had to have opened the curtains. Dean closed them after throwing away the note. He walked over to the fridge to grab a beer. Dean had nothing to do all day so he got so bored he started cleaning...He was really bored. Dean made his bed and was in the process of making Sammy's when he noticed a reddish smudge on his sheets, Dean figured it was something from their last hunt. Dean continued to drink more beer, eventually becoming drunk. It was dark outside and Dean was drunk as hell. Dean was still drunk when Sam walked through the motel door...