It's a theme shared by most parents of teenage girls.
"You shouldn't wear a dress that if you bend over, you show what God gave you," one parent told us.
But this prom season, girls are daring to wear dresses inspired by the catwalk, Hollywood celebrities. And get this, prom dresses even are copied off the dance costumes you see on prime time TV.
"It's not supposed to be taken literally, it's for film, it's for TV presence," stylist Stevie Bingham said. "It's not supposed to actually be worn at a high school prom."
In dress shops and stores all across Houston, battle lines are being drawn.
"Prom is supposed to be, this is your last chance, you need to show 'em what you got," senior Sophia Heding said.
We found Heding trying on a few prom dresses for her father, who was laying down the law.
But this year, parents aren't the only ones implementing strict prom dress rules.
HISD says each of its nearly 40 high schools creates its own prom dress code. Chavez High School administrators say their rules are plain and simple.
"We don't want them to show too much cleavage and too much sides and the back it should not go below the waist," assistant principal Reesa Turner said.
For short dresses, students must follow the finger rule.
"As long as the dress comes right here, at the tip of her finger then that's an appropriate length," Turner said.
Some parents feel schools should go back to the rule known as "the floor test," where you kneel down and if your dress doesn't touch the floor, it's out of prom dress code.
But when it is too short, too tight or shows too much skin, who's really responsible for policing the rules -- the parents or the schools?
"I think the parents," one parent told us.
"The parents, they are the ones that are paying for it, they're the ones that can say," another parent said.
"I think its parents No. 1. That's my own opinion. I'm not going to let my daughter go out in something that I haven't approved of," a third parent said.
School officials we spoke to say they're aware that the styles are sexier than ever; so, this year, they're hoping to work with parents, making sure prom season is full of good memories and good taste.
Heding's father says he couldn't agree more.
"She is 19. She is grown, in a sense, but, like I said, this is her last 'hurrah' that she may have to hear my mouth about anyway," he said jokingly.
If you're battling what's appropriate for prom with your daughter, we've got some expert advice from a Houston family therapist.