Bastos - a Filipino word which translates to being "rude" or "ill-mannered". Or commonly in filipino context, a sex maniac.

Beystos - Slang for the above, typically the way westerners would try to pronounce the word.
(Boy groping a girl's ass from behind): hmmm...
(Girl turns around, in anger and defense, bitch slaps the boy and yells):
BEYSTOS!
by mmmmanoy March 30, 2010
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