so I wasn't paying much attention to what was going on around me.

Until I suddenly looked down

and realised that the man sitting next to me had his hand on my leg.

He moved his hand upwards and grabbed me in the crotch.

Because I was on the phone to my mum, I said

'I'm on the bus, this man just groped me.'

And everybody on the bus heard me.

And everybody looked away.

Nobody stepped in. No-one challenged him.

No-one even made eye contact with me.

And it sent me such a powerful message.

It felt like they were saying,

"We don't want anything to do with this. This is your thing."

It made me feel that I was at fault, that I'd done something wrong.

I felt incredibly embarrassed and ashamed and confused,

and I got off the bus at the next stop

and walked the rest of the way home.

Looking back, I wasn't the only person

who got such a powerful message that night.

So did the man who groped me.

He got the message, "You can get away with this."

It sent the message that this was just acceptable.

We're so used to receiving the message from all around us

all the time, that women and girls are sexual objects.

That our bodies are public property

and that we really are the sum of our individual parts.

There are witchcraft cases from Europe 400 years ago

where, for example, a woman was accused of witchcraft

for giving a man a 'permanent erection'.

The idea that men couldn't possibly be expected to control themselves

is nothing new.

But it's also something that's still really impacting people's lives,

even today.

Now were you able to wear undergarments?

You're like the fifth person that's asked me that today.

Well, no, because, is it inappropriate?

-To ask somebody what kind of underpants they wear?

-I didn't ask you what kind.

You just asked me if I was wearing any.

-Could you? -No, what do you wear underneath?

What do you wear underneath something...

Overalls.

-Do you wear clothes?

You wear dungarees. You can't wear clothes under it it's like a wetsuit.

-Practically. -OK, so you answered my question.

Well I don't know, maybe it's a little bit more than a wetsuit.

Was I wearing underwear? I mean, gosh.

I think the defensiveness here is really key.

This idea that he is immediately reaching to say,

"Well I haven't done anything wrong, you're overreacting."

And that he kind of gets a little bit of support for that

from her male co-star, and this is something that we see a lot of,

that if women try to challenge this kind of thing, try to speak out,

often there can be a closing of ranks

in a sense of, "No, no, no, you don't get to be upset about this."

In most British homes, parents clearly differentiate

between their sons and daughters.

But not in this north London household.

Here they aim to bring up their children

in what they call a non-sexist way.

I think what's really sad watching this now

is that it still feels a little bit revolutionary.

Wouldn't be fair for all the girls to buy princesses

and all the boys to buy superheroes.

Why?

Because girls want superheroes and the boys want superheroes.

And the girls want pink stuff and the boys don't want pink stuff.

-Yeah. -Yeah.

She makes it sound so simple, doesn't she?

How is it possible that this child gets it

and yet every time a large retailer agrees to stop gendering its toys

or its children's clothes as for boys or for girls,

you'll see a backlash in the press?

These kinds of stereotypes that are so insidious and so low-level,

they are so often dismissed as not a big deal.

In reality all we're saying is that kids should have the choice.

That, just as she says, some girls might like princesses

and some might like superheroes, but shouldn't they have the option?

The reality is that fewer than one in ten of our engineers is female,

and our Royal Society, one of our biggest scientific institutions,

has never had a female president.

So no, of course these things aren't the end of the world on their own,

but do they contribute to a world in which girls are very, very gently

and slowly told, "This isn't for you, this isn't for you"?

Of course they do, and actually the end effect is quite extreme.

Andy, Sam is the first US player to reach a major semi-final since 2009.

How would you describe-- Male player.

I beg your pardon?

-Male player, right? -Yes.

We are seeing an increasing number of male role models

who are choosing to step in

and just to mention this stuff when it happens.

Not necessarily in a particularly aggressive or angry way,

but simply just mentioning it so that that isn't allowed to stand.

If you haven't experienced sexism yourself,

like with other forms of prejudice,

it becomes much easier to ignore

and to deny the reality of its existence.

It's easy to suggest that people are overreacting,

that they must be making something up,

because you haven't seen it.

Essentially, the truth is that we can't change this

as long as everybody just thinks it's normal.