What if Sam killed John and yellow-eyed demon?
"How's he doing?" Sam asked when Dean walked into the room.
"He's OK. He just needed to rest. What about you?"
"I'm fine," Sam answered. "You saved my life back there."
"Guess you're glad I brought the gun then," Dean taunted.
"Look, man, I'm trying to thank you," Sam said.
"You're welcome," Dean relented. "You know I killed a human, too." That was really weighing on him. He had never killed a human before. Maybe he had failed to save some, but never actually killed one.
"You didn't have a choice," Sam said, trying to make him feel better.
"I know. That's not what's bothering me," Dean said, not sure he could explain.
"Then what is?" Sam asked.
"Killing that guy, killing Meg, the things I'll do for you and dad. It scares me."
"It shouldn't," John said, walking into the room.
"You're not mad?" Dean asked in surprise.
"Mad?" John asked.
"For wasting a bullet."
"I'm not mad, I'm proud of you," John answered
Dean thought that was odd. "You're proud of me? You've never said that before."
John looked taken aback for a minute. "Well, I've always felt it," he said.
"You're not my dad," Dean said and pulled out the Colt.
"Dean what are you doing?" Sam asked.
"He's gone crazy," John supplied.
"That's not dad, Sam. Dad wouldn't be proud. He'd be pissed I wasted a bullet."
"Well, if you're so sure…" John began and then lunged forward to attack Dean, causing the gun to go flying out of his hand to the floor.
While John and Dean were fighting, Sam picked up the gun.
"Who are you?" Dean rasped out.
"I'm the one that killed your mommy, and Jess," he said turning towards Sam, his eyes glowing yellow. It was then he noticed that Sam had the gun pointed at him.
"You can't kill me, not without killing daddy, too," it sneered, and turned its full attention back to " sDean and sparked red, just like the vampire last week.
Dean recovered his breath and said, "Sammy, how could you?"
"I didn't know what else to do," Sam answered guiltily.
"You should have just let him kill me," Dean yelled.
"How would that have helped?" Sam asked. "Dad might have been dead already, anyway." That was a lame defense and he knew it.
"Sam, family has always been the most important thing to us, and you just killed dad. How can you even try to justify that?"
"Dad would have wanted me to. He wanted that demon dead more than anything," Sam knew he was rationalizing, but he couldn't take it back now. He had killed his father. "I did it to save you."
"Sam, why don't you go back to school? I don't ever want to see you again," Dean said and slammed out the door. Sam heard the engine of the Impala roar to life and it sounded like Dean was burning rubber to get away from him as fast as he could.
but poor Sam just can never catch a break and I had to help him out a little.