Why do girls have to wash thier bras, seems funny to me to do it...?

If your bra isn't washed after every 3 to 4 wears, it can start to accumulate dirt, oil, bacteria, and sweat that comes off of your body. ... (Speaking of sweat, it should go without saying that your sports bra should be washed after every workout.) The type of bra you're wearing can also have an affect on its grime level.

To remove the boob sweat that forms from wearing constrictive clothing.

Why does anyone wash their clothing? So they can wear clean clothes.

Cause we sweat that is why

Body oil build up goes rancid after a while. Bacteria blooms increase too.

They can get sweaty and stinky.

if you wore a singlet every day would u want it washed

Because there nipples stink and leave a stain on there bras. Same with guys we wash underwear because it is worn or has skiddmarks.

Same reason you wash your pants.....or don't you? pooh

Hygiene. Maybe you’ve heard of it.