What is it with the middle age folks thinking the belly is provocative? It has nothing to do with Miley Cyrus or Taylor Swift. It is a throwback to the 70's popular midriff style. In the 70's, we had way more skin showing with our midriff peasant blouses tied right under our boobs and way, way low jordache hip hugger bell bottoms, preferably with a belt made of the same material as the top.
I middle-aged and I don't think the belly button or midriff is provocative.
What I grapple with is what looks "classy" as a formal occasion. I have seen two piece dresses that look formal and I've seen some that look downright tacky. The same could be said for many of the one-piece prom dresses that are out there. Some off them look ridiculous.
Everyone has an idea in their mind, based on how they were raise, as what constitutes appropriate dress for various occasions. Proms historically have been long, flowing gowns. Over time, society's perception and rules about what's appropriate definitely change and the "old" folks have a little trouble there adjusting their ideals on that.
I think it really all comes down to good taste. There are some people that can pick the *right* two-piece dress and pull it off beautifully. And there are some, as evidenced by my Facebook feed, that have no idea that they look horrible in something and it's not right for them (this goes for "normal" prom dresses also).
To me, the prom will always be the ONE formal occasion in high school where you display elegance, formality, "pomp and circumstance," at the end of your high school tenure. No matter what the styles are, I think everyone should strive to look formal and elegant. Unfortunately, many girls in the age range (DD included back in her day) want to look like something off a reality TV show. There's a happy medium.
Again, no problems here with a two-piece prom gown, but keep it classy!