Are visible nipples really a big deal?

Every woman has experienced her share of embarrassing moments due to what some call "spontaneous nipple erections." Whether wearing an overly clingy top, or experiencing a rapid drop in temperature, there's little one can do to prevent her nips from showing. That said, bloggers and commenters alike have spent the past few days hating on Megan Fox (left) and Heather Graham (below) for letting their nipples show.

Many dresses made for formal events are low cut, backless, one-shouldered, or very wispy silks. It's impossible to wear a bra under such garments, and even if you could, who wants to interrupt their gorgeous fluidity with bumps and straps protruding from underneath. Sure, pasties are an option. But should they be necessary? Is a little nip action really inappropriate and scandalous?

In fashion spreads and runway shows, no one wears a bra unless the actual undergarment is fundamental to the look. Designers would rather have the models' nipples poking throug--or even be put fully on display--rather than ruining the way they desire the fabric to drape. If designers, models and fashion editors can be mature about bare breasts, why is it that every time a celebrity walks down the red carpet with her nipples protruding the world freaks out about it? Is there a disconnect between the fantasy fashion world and real life?

We remember a time when a little visible nip was desirable. Years ago in "Sex and the City" episode #54, Samantha lends Miranda a pair of silicone nipple enhancers, telling her that erect nipples turn guys on. On the show, they work. There was also some speculation several months back about why Jennifer Aniston's nipples are always at attention--several blogs claimed it was the work of "pokies" enhancements, similar to those Miranda wore.

Are nipples sticking out a good thing or a bad thing? Now we're confused. We know they're responsible for some awkward moments, but it seems they also warrant loads of attention, both good and bad.

Do you think it's ever OK to not wear a bra? Do you think women must, at the very least, cover up their nipples with pasties? Why do you think nipples are such a big deal? [WWTDD][Best Week Ever]