This can be applied vice versa with girls looking lustfully at guys as well, but I'm mainly talking about guys looking at girls in this question. I've seen in the Bible it says that if a man looks at a woman lustfully then he's committed adultery with her. But if a guy looks at a girl with lust, is she to blame or is it just him? Even if the girl is just wearing normal, non-revealing clothing?
Firstly, let me answer that the girl is not to be blamed no matter what she wears. What a girl wears, whether revealing or non-revealing, is a matter of her individual choice and preference. There is no blame on her. If a guy looks at a girl in lust that is his own perverse thinking and upbringing which is no way to be blamed on the girl. Though I do believe finding a girl attractive or hot cannot be termed as a 'sin' per se, but if a guy is crossing his boundaries and coming on to a girl sexually on in an intimidating way without her permission it is wrong and should be immediately stopped. And such a behavior is a sin for only the guy. Not the girl.
It's a grey area, I don't believe it's the girls fault, you could say the girl is dressed in revealing outfits, but if you don't think she's attractive to begin with, you don't suddenly get all 'lustful' about it because she's now in more revealing clothes. I'd say it's the guys fault, yes guys do have hormones, I have hormones but the difference is I can control them... guys who are slaves to their hormones I'd consider to be at fault as they're somewhat weak willed.
It's not the guy's fault since it's his biological urge (which "god" gave him) which causes him to lust after a girl. It's also not the girl's fault since it's her right to wear whatever she wants. Although, there is a correlation between revealing clothing and lust.
What the bible is really getting at is: Don't fantasize about women when you're in a relationship because it's just as bad as cheating.
Who cares? A guy looking at a girl lustfully isn't wrong unless he's in a committed relationship and is looking at a different girl that way. We all have hormones. It doesn't matter what a girl wears. Wearing wearing figure flattering clothes isn't a sin. And it's not a sin for guys to appreciate it. I won't take advice from a book that's thousands of years old.