It's fairly well established that
violent media has a detrimental effect on children. Only one study concluded anything positive--and that was that with significant parental involvement, the effects of violence are mitigated. This would probably extend to sexualization.
(Off with science goggles)
Sadly, I watched this. AND NOW I CAN'T GET IT OUT OF MY BRAIN. ARRGH.
The problem I see here is that everyone seems to be thinking of children as mini-adults. They're not. They primarily want to 1) Run off and do something outside of their parents, and 2) Get their parents to accept it and praise them. What their parents praise or condemn them for becomes what they feel like they're expected to do or not do to gain acceptance from society. If they do something in line with their interests, and people praise them for it, then they will be profoundly happy. Their interests will be funneled down this channel, so they'll generally end up with what their parents encouraged as a very influential starting point. (Assuming a relatively healthy childhood.) This is pretty much how raising kids works.
You can see that the parents either don't care about this, or, more likely, are actively encouraging this. So the kids are learning that they should do what, now? I mean, there will always be a market for strippers, for lapdances and such, and I'm sure that they can land a decent position as a trophy wife with a little grooming, but... this is a highly sexualized dance that they're being praised for.
Now, nothing's wrong with sex, let me point out. But if your entire life, if your entire interests and such revolve around sexualized displays, then something's wrong. And, trust me, for that dance routine to come together, they've had to work with those kids for a long time. Intensively. These kids were eating, breathing, and sleeping their dance routine. And then they got a lot of praise for it. So, what have they learned? Maybe determination. Maybe how to dance a bit. But probably? They'll look back on this as they get older and think this is how to win over the world. Probably not just because of this, but because of several incidents--this sort of thing is indicative of poor parenting.
The "they're happy" defense just doesn't do it for me. They'd be just as happy dancing something less sexualized, and be far better off in the long run. It's like someone came up with a self-defense system for little kids, where they went through basically boot camp, and were trained how to hit someone until they bled, how to use a knife, were exposed to a little bleeding, and were taught some fighting techniques. (It would have an ultra-hardcore name, like Kidnap-Prüf.) Would the boys have fun learning this stuff? Sure. Would they be messed up by it? A little. Would they be better off in a different martial art? Hell. Yes.