My partner has a female identity
What's a female identity? Can you clarify that without resorting to hackneyed and trite stereotypes? Being transsexual, I've never had a "female identity", only my OWN identity. Surely having a "female identity" is just appropriation? Just curious what a female identity actually is.....
and would not behave this way in "girl mode"
You realise how offensive that phrase is to women right? Not only does it sound infantilising but it's demeaning to the lived experiences of women. It's misogynistic, ridiculous and sounds akin to putting on 'womanface'
Being a woman/girl is not something you can put on and take off like a costume - because no matter how many dresses they wear or how much makeup they put on, they can never change sex and actually BE a woman/girl.
Saying that - there's absolutely nothing wrong with crossdressing or mucking around with gender stereotypes, as long as you're not infringing on the rights of others (or causing offense) while doing it.