It's like a Monty Python sketch.
'Straight women never see vulvas!'
'Well, apart from those straight women who used a mirror to look at their own or maybe when they were learning to use a tampon...'
'Yes, apart from those'
'...and of course straight disabled women who use catheters...'
'Yes, apart from those'
'...or are nurses or carers...'
'Yes, apart from those'
'...midwives, urologists, gynaecologists and...'
'Yes, apart from those'
'...beauticians...'
'Yes, apart from those'
'...or have female children or for a different reason I haven't thought of.'
'Yes, apart from the striaght women who have used a mirror to look, to use a tampon at first or to self-catheterise, are nurses, carers, midwives, urologists, gynaecologists, beauticians, have female children or for a different reason you haven't thought of - straight women never see vulvas'