why is it ok for our sisters to borrow their brothers boxer shorts but if the brothers borrow their knickers we are perverts

Why would your sister want to borrow your underwear....

From experience, every bloody woman i live with steals my clothes, its because my boxers fit them or are too big which isnt much of a problem,on the other hand i could not fit everything into their knickers and if i could its be painful

LOL. I can see where you are coming from here. The reason why a person might want to 'borrow' a pair of knickers I can understand; I cannot relate, but I can understand that such men are out there and I wouldn't judge anyone. But I can see where it might appear there is a double standard somewhere, amidst what appears to be somewhat a conundrum :-)

What??? I´d never do such a thing...Puajjj!...lol

I use to wear my brothers boxers but i don't want them to borrow anything to me

Good question. And it isn't just about underwear. There was a time when women wearing trousers was controversial but to day it is commonplace unlike men wearing skirts.