You asked for the most important but everyone is hedging with several… after some reflection I will say courage. Courage in a partner plays into our relationship in a multitude of ways; primarily, the initial courage to approach me in public, the courage to be charming in the face of being insecure or threatened, courage to overcome my own shyness, courage to break down my walls, courage to suggest we take things to the next step. Courage is a rarity among men (my preferred partners) and especially in the geeky sphere of things it’s almost non-existent. Courage is sexy as all fucking hell.