Let's get real: when was the last time you washed your bra?
And before you pretend you're a clean adult who has totally got her life together, we're not talking about your sports bra.
No, we're referring to your everyday bra you wear to work, give a cursory sniff as you take it off, and then chuck back in your drawer to wear tomorrow.
While many women may not be willing to fess up to the dirty truth, we all know that there are different rules when it comes to washing one part of your underwear compared to the other.
While knickers are on a definite one-wear-wash policy, their neighbouring undergarments can be afforded a little more slack.
But how often should you be putting it on a hot cycle, and is everyone else doing it is as much as they claim they are?
How often should I wash my bra?
You can all breathe a sigh of relief as we don't need to be washing after every single wear.
According to Good Housekeeping Institute's Lexie Sachs, every 10 days, or three to four wears, is enough.
But what about boob sweat?
Every woman knows that on those hot and humid days (or when you've been commuting to work on public transport), the band of your bra can get a little gross and feels in need of a rinse.
In those instances, Sachs says use common sense and wash it more frequently. She explains: "Washing gets rid of the oils and germs that accumulate, so the more oil you're producing, the more frequently you'll need to launder your bra."
Why should I not wash it more?
If you're feeling a little uncomfortable about not getting a regular wash, then be reassured that not doing so is going to help your underwear last longer.
This is because over washing your bra can damage the elasticity, which is "essential for providing the proper support", says Sachs.
Not only that but everyone has experienced when the under-wiring takes revenge and tries to stab you in the ribs as it emerges from under the cup - a fate made more likely by being put in a washing machine regularly.
Sachs said: "You should have several bras to rotate through to avoid stressing elastic over time, but wearing the same bra two days in a row isn't an issue."
So how is everyone else washing their bra?
Now, despite what the experts have told us, we're still not fully settled on this matter, not least because we're convinced everyone around is us lying when they say they wash their bra more than once a week.
In a Reddit thread, the most popular answer, read: "Honestly? Like once a month. Sorry, I know it's gross but they don't smell and I don't get acne or anything from them. And if I wash them too often they get ruined faster. I have six or seven that I swap out, so I end up wearing a bra like 4-5 times before a wash."
Another said: "Tits dont really smell when they sweat and bras are expensive. I agree go for the jeans rule. Only when necessary."
In a slightly more scientific survey, a Twitter poll by The Pool, found that out of over 6,000 women, the majority (37%) would admit to washing after a week of wears, while 30% were opting for the two plus wears rule.
Then there was the 27% who were brave enough to claim they did less often.
And as for the 6% who are washing their bra after every wear, we have one question for you, how much money are you spending on underwear here?
Well, after some inconclusive evidence, it seems the jury is still out.