I watched clips of the movie and I recognize that yeah this dancing is sort of sexual. But they're fucking kids. This isn't arousing or titillating for me so I don't really find it obscene. Kids do this all the time in their rooms and with friends, it's not like the director is making up impossible pretenses for the kids to dance like this. There's also complaints about close up shots of butts. Clothes butts. Go watch the olympic gymnastics and you'll see a lot more butt there nonstop. The mere existence of a 12 year olds butt is not a sexual thing.

If this movies makes you uncomfortable then please stay away from kids or reevaluate why you're sexualizing a child who's just dancing in imitation of an adult.