depends what kind of a guy he is, hairstyles usually match their personality/behavior. well at least that's the way I like it.
sweet/innocent guys-->longer hair but not girlie hair (I hate when they have a nice head or hair and its the perfect length and it looks really sexy and they suddenly decide its too long and cut it off, then they look kinda cute, but they used to be HOT)
bad boys/eccentrics-->shorter hair is what I prefer
it also just depends on his face but those are the majority
i'm just saying if you don't wanna be called a f** by other guys, longer hair isn't he way to go. In my opinion I love buzzcuts/ short hair, but A LOT of girls like medium length. it depends on your personality. I like rebels/metalheads and I think they look their best with buzzcuts. rofl. you're safe with short hair tbh.
It depends. Long hair only looks good if a guy has wicked straight hair or curly hair.
it really depends on the guy I've liked guys with all diff styles from short to a bit long like chace crawford long I mean, nothing longer thaan that haha, and I don't like completely bald either but short ones like adam levine are also sexy
girls aren't too particular about hair on men at all don't even worry about it