And they're not the only ones...
The bizarre eBay event that launched this week sees 37 stars sell off some of their favourite smalls in aid of NNLSDropin, a charity in support of destitute asylum seekers.
The pants have all been customised by the stars in question and can be bid on at eBay.co.uk now.
The full list of stars selling their underwear is:
Daniel Day Lewis
Sacha Baron Cohen
For more on the auction head to , and find out more about the auction on Rickygervais.com.