The Littlest Winchester

Whats going on with Sam & Dean

I woke up with my face pressed against the door of the impala with the sounds of Sam and Dean talking about music.
"Dean your really need to update your cassette tape collection," Sam stated.
"Why?" Dean asked just as confused as I was. Those cassettes were filled with classics.
"Well for one," Sam started "there cassette tapes, and two black Sabbath, Motörhead, Metallica. It's the greatest hits of mullet rock."
"Well," Dean said "house rules Sam-" I cut Dean off by saying
"Driver picks the music, shotgun shuts his cake hole!"
"That's my girl!" Dean said
"Hell yeah!" I replied. Dean started smiling, yet Sammy just kinda dropped his head like he was feel guilty or something. But why would Sam feel guilty?
"So how did you sleep?" Dean asked
"Okay," I replied. "I would have slept better if I had an actual bed though."
As soon as I said that Dean turned up the Mötley Crüe song that was playing and held his head low. But now Sammy was smiling. There was something going on between these two, and I am going to find out what.