Cupcakes and Werewolves
More than a few twelve year olds are sexually active.
More than a few twelve year olds have parents that don't care.
They look young, but they're not stupid. It's easier that most people realize to fool someone when you're that age. Things can come to you quite easily and effortlessly.
I say if they want to wear skimpy lingerie, let them. It's not anyone else's issue. Furthermore it's not surpising in our society. We market sexuality. Of course kids are going to want to get in on it. Plus, most of those "twelve" year olds go in for the Pink stuff, the fragrances, the lip gloss, and perhaps the occasional well made bra. I mean. If you're pubescent you're going to need one- why not get one that is made well? Denying kids the access to this stuff isn't going to solve much. They're going to find other ways to get it or they're going to have whatever sex they've been having anyway.
Except that it is illegal for them to have sex, and it is dangerous for them to become pregnant. It is illegal for a reason.
Until it is not illegal, it is in fact anyone else's issue.
Also, it may be easy to fool people at that age, but I would contest that it is easier to be fooled and manipulated. I believe that there are probably very mature 12 year olds out there, but it seems unlikely that they make up the majority of the ones who have sex. In general, 12 year olds who are having sex are being taken advantage of and should be protected.
Underware is underware, and sex is alluring, but if 12 year olds are having sex or are in sexual relationships, they need help.