Bra?

Just had a customer buying a black shirt and made a comment about he had made the mistake of wearing a white bra with a blue shirt and I thought I must have heard him wrong but as he walked out of th store yes he was wearing a white bra and his blue shirt was see-thru for everyone to see. The obvious question for me is UMMM WHY WAS HE WEARING A BRA IN THE FIRST PLACE!?!?!?!