twat beat: (twat beating).
'When the dominant of two females agressively slaps (hits hard, beats) her vagina (pussy, twat) on the other felmale's vagina to inflict pain, discomfort and/or damage.'
See also: I'm a bad bitch.
"I'm so mad at her, I would 'twat beat' the shit out of her!"
If your friend was born august 24th tell her/him that there a bad bitch