YTA.

You’re the MEGA asshole because your reaction to this sudden event was solely concern that she didn’t adhere to your ideas of “proper behavior, rather than concern about what issues might have prompted this sudden behavior.

• Were all the other girls at school doing this, and your daughter was (absolutely normally) simply following current fashion trends?

  • Was your daughter being teased about her body, and dressing this way in response?

Both of those situations are important and should be properly addressed - but rather than figure out what’s going on with your kid, you went all “must punish for looking like a stripper!”

Hey, let’s talk about that too.

She looked like a damn stripper.

And

for wearing basically fake jugs to 4th grade class?

So, I’d naturally describe your kid’s actions as “stuffing her bra” - something lots of girls do in an often innocent attempt to look older. You, on the other hand, described your kid’s actions in a highly sexual manner. Unless you have some clear basis for thinking that this was a deliberately sexual behavior instead of a rather common young girl behavior, your perception of your kid’s behavior says a lot more about YOU than it does about her (and what it says about you is not nice).

But let’s get back to likely possible reasons for this behavior:

• she’s responding to being teased for her appearance (maybe classmates also call her “a twig of a kiddo”?)

Body image is a super important and touchy topic for young girls. If this is the explanation, then there’s a serious matter that your daughter needs guidance and support on.

• she’s trying to fit in with behavior of other girls in her class and/or meet some fashion standards of her social group with no sexual intent

This is more nuanced, but based on your stances would likely warrant a discussion on following the behavior of others, making independent choices, and what is acceptable behavior (and why).

• it’s just a “fun thing” that she and/or her friends did for no real reason, like playing dress up (no sexual intent)

In this case, you should just let it go; don’t create an issue by imposing adult issues on innocent childish behavior. That’s gross.

• she’s specifically trying to look sexier (there is “sexual” intent of some sort)

This last one is, IMO, the least likely - but if it’s the explanation, all the more important that you talk to your kid openly about the underlying issues. A ten year old trying to be sexy IS cause for concern IMO ... assuming that’s what this is.

Regardless of the explanation for your daughter’s behavior, you failed. Asshole.

Handling this situation properly - by which I mean, identifying the underlying issue here in order to provide your daughter with the type of guidance, support, and/or rules that she needs to develop in a healthy manner - requires talking to your kid like she’s a human with thoughts and feelings.

You’re an asshole because instead of giving a damn about what your kid is going through to engage in this behavior, you freaked out and punished your kid because you didn’t like the way she looked (based on standards that she’s literally never even considered because she’s 10!).

That’s fabulous for building a trusting relationship where your daughter can come to you with questions and issues, and a great way to teach a little kid to develop good values and judgment that she can independently apply to new situations as she grows up. Oh, wait, I got that wrong: you did a TERRIFIC job teaching your kid to hide the bra before she gets home next time. Gotta hide things from Mommy or she’ll go psycho and steal my toys!

TLDR: you’re an asshole because you were a bad parent at an important moment. Also, you’re a dick towards your in-laws.