Kids. They grow up so fast.

Really, really fast in Taylor Momsen's case.

The Gossip Girl star's fashion sense is something else.

Last week, Taylor stepped out in NYC wearing a revealing outfit with some guy we thought could be a boyfriend, but is also rumored to be her cousin.

In any case, she made headlines by showing some skin at 16. That was tame compared to the ensemble she wore at Fashion’s Night Out Friday:

She wore it to perform with her band The Pretty Reckless, but she's still wearing a sheer button-up, a garter belt, and sequined panties. Gulp.

What would Rufus Humphrey think?

We know Taylor's, like, a big star and everything at this point, but ... 16. It's hard to get past that. She can't even drive after 9 p.m. in some states.

Do you think Taylor Momsen dresses too provocatively for her age?

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.