You're an idiot.
A fetishes is an attraction to something you're not conventionally supposed to find attractive. Tits are not a fetish. Positions are not a fetish. Maids and teachers or swimsuits are a fetish.
"BUT SWIMSUITS ARE ATTRACTIVE FAG"
No, shut the fuck up, be ing more attracted to a girl in a swimsuit than a naked girl is not conventional.
A perversion is being attracted to something you shouldn't be. A fetish is being attracted (or aroused I guess) more than usual by an object or quality of a person. There's some overlap there, but a fetish is dependent on just how much everyone else likes a thing. So if you like feet a lot more than most people, you have a foot fetish. If you like little kids, you're a pervert.
This common usage is an annoyance.
To me fetish denotes something required to achieve sexual arousal but few people would limit themselves to such a narrow definition.
Words evolve, bothersome as that can be, or we'd all still be speaking Latin.
Sometimes to leaves things to the imagination
If she's wearing a revealing shirt it means she actively wants to be attractive to everyone who looks at her and not just the guy she winks at. If she's just not wearing anything then she happens to be attractive. Women often instinctively try to make themselves more attractive to every possible mate deliberately when they're ovulating, and most fertile. Deliberately revealing clothing therefore is like advertising high reproductive likelihood.