So when the wife comes to you and goes "I have a problem, blah blah blad....do you think I should do A or do you think I should do B"
you think about it and say "Well I think you should do A"
she then goes "No, A is no good, maybe I should do B"
then you go "Ok, then you should do B"
then she goes "No thats also no good she thinks that she should do C"
then you go "Do whatever the f*ck you want"
then she's cross with you for a week.
Now, when you go to her and say "I have a problem, should I buy a V8 or a superbike"
she goes "Do whatever the f*ck you want"
....and you buy the bike then she doesn't speak to you until you return it...
It seems to me that the phrase "Do whatever the f*ck you want" means "Do whatever the f*ck you want because I really don't care one way or another" to a man
and "I am going to be cross no matter what you say or do because this matter is very very important to me" to a woman