Im a straight male and enjoy watching all combinations of male or female play. For me, M/m scenes I like to top or watch are non-sexual. With the sexual element removed, the good scenes can range from cold and clinical to matter of fact punishments where the bottom is challenging the top and taking it well. It is then all about the CP and the interaction chemistry of those playing. It is hard to describe what in a specific M/m scene makes it work. Maybe others have considered this aspect.