Being American I never hear anyone say twat unless they're from the UK and usually I hear it rhyme with hat. I do, though, remember being called a twat by a British person. I thought it was fucking hilarious.
My buddy," Why is that so funny?"
Me: "I'm pretty sure he just called me a vagina."
My buddy," Why is that so funny?"
Me: "I'm pretty sure he just called me a vagina."