Oh, to be inside the heads of the dads taking their grade-school daughters to see the new Britney Spears tour, once it dawns on them they’re initiating little Suzy into the sort of erotically fixated experience more commonly shared over a business lunch at Scores. About the time Spears strips down to a flesh-toned body stocking, getting all Divinyls on herself during ”Touch of My Hand” — which also features male dancers humping bedsprings and one another, with silhouetted threesomes in the scaffolding for good measure — you can almost hear a mantra among the arena’s adult male chaperones: Please, God, don’t let this come up in the custody hearing.

Of course, umpteen ”not that innocent” fair warnings later, families were in shorter supply at Spears’ sold-out L.A. Staples Center gig (an early stop on a tour that runs through Aug. 11) than packs of teen girls, many of whom looked like they used Thirteen as an instructional video. What they see in Spears, beyond hypersexualized role modeling, isn’t hard to suss: Girlfriend works hard for the money, keeping pace with better-trained dancers through every step of the choreography — even if holding her own sometimes means that, when her otherwise dead mic goes live for between-song chat, she’s panting like an emphysema victim. In any case, compensating for vocal limitations with serious Protestant-work-ethic hoofing is no small accomplishment. In Britney, Paul Verhoeven’s fantastic notion of the showgirl as superstar has become incarnate.

But every showgirl needs a show. The Onyx Hotel tour hardly counts as one, with its arbitrary mishmash of Madonna-esque sex-bomb skits and Cirque du Soleil surrealism. (The hotel theme seems to exist only to have Britney on a luggage cart, passed between topless bellboys, or to occasion a short film where she undresses for hotel security cameras.) Even the patter is canned, as when Spears confesses each night that ”the last couple months have been kinda like a roller-coaster ride…but I think at the end of the day it’s made me who I am right now.” Which is…who? At the end of 90 impersonally horny minutes, it’s still only her trainer who knows for sure.