Its all fair game in our house. I cant remember whose is whose anyway and being boys "if its in my room I will wear it" undies, socks, tee shirts its pretty much only my bras and undies that they wont wear

I will hand undies down the line in my family but not if im handing stuff on outside the family.
My Mum is an avid op shopper and quite often picks me up really pretty Bras for $1 or $2 and they are practically new! Huge savings on the $50 or $60 it usually costs me for a decent bra.
I have no issue with wearing them however I wouldnt wear someone elses knickers