13 year old girls might want to dress in sexualised clothes, thigh high stiletto boots, push-up corsets, and shorts showing their bums, for example.
I would not be happy for my DD to do so. Let me think aloud about why.
It's not because I think teenage girls invite rape in those clothes, or that there is something intrinsically sexual about their legs.
It's because society tells us all the time that those sorts of clothes have a meaning; that the wearer is a (strongly/hyper) sexual being. You will see the images portraying this in all sorts of media, music videos, pornography etc.
The message is also that this is how the women get their worth, their power, through their sexuality.
An innocent 13 year old may not have analysed all this.
But to everyone else who sees that uniform, there's a clear message - sexuality.
Why deny that some clothes are seen as sexual?
Rapists rape because they're rapists.
But a 13 year old in sexualised clothing will be coded by others as... Stupid? Worth less? Not worth looking out for? A target for grooming? Not looked after by her parents, so vulnerable? A bad kid? Off the rails? Likely to drink/be drunk? Trying to seem older? Troubled? More likely to agree to consensual sex? A risk taker?
Sexualised clothing gives all sorts of messages that we perhaps wish it didn't, but, in this world, it does. Unfortunately there are always some people who will want to exploit others. Many of those messages could read as an invite to them.
It's not the same for boys as girls, because men and women are treated completely differently in society, about their sexuality! Would I think it appropriate for a 13 year old boy to wear tight shorts showing his bum cheeks? Well no. But who is going to think about wearing them? It's far more possible that a 13 year old girl would than a 13 year old boy! So that's who you end up having the conversation about.