Why Beat The Person

Cheating

What would you do if you found your boyfriend cheating on you?

I asked my friend this question and the answer I got was beat the woman then beat him so with that I got angry why would you beat the woman first when she isn't the one who is cheating on you he is she says the woman had to know that the man is taken.  That just got me confused how is the woman supposed to know he is taken and how can you make that assumption that the woman knows that he is taken she says she has to know because it is obvious that he is taken.  To be honest you never know if someone is taken or not unless you know human behavioural characters and not everyone studies that at all.