From the stereotype of a pimp's demeaning and abusive treatment of his prostitutes, whom he refers to as his bitches. Those who use the term typically see themselves as being superior and as being in a situation that calls for them to mete out harsh, abrupt, and abusive treatment for what they perceive as stupid or disrespectful behavior--or simply when they think such treatment is needed to remind someone of her inferior status. Example: You talk back to me one more time, and I'll bitchslap you.
BITCHSLAP
Meaning of BITCHSLAP in English
Slang English vocab. Английский сленговый словарь. 2012