Don't get it twisted: I'm a whore for protective, possessive Dean. A Dean who nips the back of Sam's neck, whispers mine, mine, mine with every thrust. A Dean who steps a bit closer to Sam when a flirty waitress eyes Sam up and down. The kind of guy who sleeps in the bed closest to the motel door. That type of thing.
But a possessive, protective Sam? That smashes every button for me. A Sam who leaves dark, splotchy bruises across Dean's freckled hips. A Sam who destroys demons with his mind if their eyes merely fall upon Dean's form. A Sam who breaks bones, slashes throats, ruptures internal organs, all for Dean. Everything for his big brother. A Sam who uses those large hands of his to knead soothing circles across Dean's back. Those lips, pressing praise and reassurance across his temple. You know, that type of thing.