i think western meaning of 'cute' is a little different from ours. when koreans learn the word 'cute', we say it as 귀엽다, 귀여운. but we commonly use 귀엽다 or 귀여워요 to indicate babies, puppies, and small things like that :P. So, when you indicate a man, you better say '그는 잘 생겼어요, or 그는 멋져요. ' and when you would like to say 'you are so cute' in korean, you can say '넌(너는) 정말 예뻐' or just '넌 정말 귀여워.' makes sense. In conclusion, you can say 귀여워요 to someone . But, if you talk about a guy, you'd better say 멋져요, 잘 생겼어요. and if you talk about a girl, you'd better say 예뻐요, 귀여워요.

However, If one guy looks really cute (like puppies or babies...etc) of course you can say 그는 귀여워요 :D :D But I think you wanna say that in general meaning so I explained a little long :P I hope it will be helpful :)

너는 너무 귀여워요 is a formal and polite way to say this. Well if in the normal daily life conversation most of the people will go 아!! 너무 귀여워!!

koreann a very hard language to learn .... you don`t have A B C letters you have astrange shapes .......really very difficult ..^_^ ^_^