I dont see anything wrong with a straight guy mentioning that another guy is good looking. Its normal, if you ask me.
I know one thing, other girls call other girls hot all the time. So how is it any different for guys?
I do know though that many guys aren't willing to say that. I am probably one of them. There is just something about me that doens't like calling another guy attractive. Like if my sister would ask me is the guy hot, I'd be like, see for yourself
And no I'm not homophobic.
Its just not a guy thing.