I think as long as ladies want to make a statement and be the eye-catching divas they want to be, I don't think sexy is going away anytime soon. I don't want to believe that looking sexy is going to fade away because there are always some ladies looking to push the limits and maybe go on the risqué side. I think there is a such thing as looking sexy and still being in style. Only as long as you're not looking like jailbait or whatever or one of those hookers (is it okay to say that on here?), then you're perfectly fine. Designers are always going to try to come up with fashion items to unveil the attractive and sultry beauty hidden within fashion-conscious ladies.
The only way sexy can be out of style is if some designers convince ladies that more modest fashions will still bring the same results as, say... a slender lady in a mini skirt wearing high-heeled strappy sandals. The only way that's going to happen is if designers can come up with fashion styles which don't bare too many details. And a lady is going to want to feel comfortable while being attractive (or at least beautiful). A little joke I would make is that sexy was showing signs of dying out when some ladies wanted to wear leggings under denim mini skirts. I haven't been on here in a while, but I did say that it wasn't very fashionable for me. Maybe a tunic and some capri leggings, but that's about it.
Maybe my general feelings are on the deal that something low cut does make one seem too much as a fashion victim of some sort. I just prescribe to the deal that love has skyrocketed since maybe World War 2. Sexy then was probably anything just above the knees. The 70s brought along a plethora of hot fashions including hot pants (still popular today) and gaucho pants or culottes based on how you wish to term them (recently made popular again; some ladies prove that they can be a year-round fashion). I guess the 80s brought along more rock-style stuff as rock music (I'm not a big fan of rock) was being popular and more grungy outfits were the rage. I should know since I was born in 1983. The 1990s pretty much provided the backbone for what we consider the modern version of sexy. There's been all sorts of love-inspired clothes as well as midriff-baring and leg-bearing objects. I'm personally not offended by all of this. A lady should be able to dress as she wants to. I have no control over any lady's thoughts. If you want to wear that low-cut top exposing your navel piercing and that mini skirt that that rides up mid-thigh, go for it. Whatever makes you feel comfortable and attractive works for me.
Sexy will never be out of style as long as ladies still want to look as attractive as they want to be. Never forget that.