Imagine Dean making jokes about your bad taste in thing and then you tell him you picked him:
I was in my room with the music up loud dancing like a crazy person.
"Y/n!!" I heard Dean yell as he opened my door. I turned off my music and looked at him. "If your going to play something, don't play trash" he said and I gasped.
"In fact your taste in music is rather awful" he said and I turned it back on and started to dance again. A little while after you went to the fridge and got some chips. "These are better" Dean said and held up his bag. I rolled my eyes and Dean kept talking about everything. "You have such bad taste" he finally said and I looked at him.
"That explains why I picked you" I shot back and his face dropped from a smile to a frown. I got up quickly and ran out of the room.