Not sure this is real. A little far-fetched.
But, school kids have been told they can't make hand gestures when they sing "Twinkle, Twinkle, little star."
Given that the British Sign Language gesture for female genitalia is a diamond or triangle shape, it is believed that the gesture was accompanying the line 'like a diamond in the sky', which is known to have caused confusion in the past.
in this video, the "offensive" hand sign at about 1:18.
Um...how has it caused confusion, exactly? Did the deaf children think that someone was claiming there was an upside down vulva in the sky? I mean, sure, that would be scary, but I can't imagine that is what they thought.
(Nod to the Blonde)