'Dance Moms' Star Ashlee Allen Left the Show Because of Overly Sexy Dances

Ashlee Allen followed Abby Lee Miller's lead and left "Dance Moms" -- but for a totally different reason ... she wasn't down with the show trying to sex things up with the kids.

We spoke to the now-former dance mom, and she told us -- first and foremost -- the Lifetime show will never be the same without Abby at the helm.

Then she lays it on us ... "Dance Moms" producers have apparently been pushing for sexier dance routines, which Ashlee says was too much for her and her teen daughter, Brynn.

Abby didn't mention anything about this specifically in her public bow out this week. Instead, she cited "being manipulated, disrespected, and used - day in and day out" by male showrunners.

There's footage of the dance number that set Ashlee off ... and it's pretty racy for 14, 15 and 16-year-olds. We've reached out to "Dance Moms" brass ... so far, no word back.