I agree with the first part. It's not perverted, IMO. We all fantasize about people who never know they are the object of our fantasies, that's just human.

I disagree that she shouldn't be so sexy if she doesn't want him to jerk off over her. I've gone through periods where I was as intentionally unsexy as I could be, and still got yelled at, whistled at, asked out repeatedly.

Pretty much, all you have to do is have a pulse for someone, somewhere, to find you sexy enough to fantasize about. And in some more bizarre cases, not even that is necessary! But it doesn't sound like she was dressed to create sexual fantasies in other people, to me.

And again, it's perfectly human and natural to fantasize, even to half hope you'd get caught and be joined in the fun (or more than half hope so! )