still trying to figure that one out myself but i think its like how girls that are friends are called "girlfriends" yet guys dont call their friends "boyfriends" so man-crush makes more sense because that means you like eachother a lot and hang out a lot but your the same kind and its not the same kind of relationship like a man and a lady ...its different.....i think that is what it means but someone can correct me if i used it wrong