Man crush is a strong emotion a straight man shows when he respects, admires and idolizes another man, totally non-sexual. Celebrities¹, athletes and rock stars are often the object of the man crush. When you have a man crush on another man, you would very badly want to be that man.

Man crush（男人间的欣赏）描述的是一个直男对另一个男人怀有尊敬、仰慕以及崇拜情绪时表现出来的那种强烈感情，而这一切与性无关。名人、运动员和摇滚歌星等通常都是男人欣赏的对象。当一个男人很欣赏另一个男人时，他会特别想要成为那个人。

For example:

Ben Affleck has had a man crush on Matt Damon for a long time.

本•阿弗莱克欣赏马特•达蒙好久了。