By Christopher Rosen
August 27, 2016 at 01:16 PM EDT
Andrew Lipovsky/NBC

Jimmy Fallon learned an important lesson about men on Friday night’s episode of The Tonight Show Starring Jimmy Fallon, courtesy of Jessica Alba: they don’t like having sweaty butts.

While discussing her husband Cash Warren and his apparel company Pair of Thieves, Alba revealed the Pair of Thieves underwear line comes with a no “swass” guarantee.

“He makes undies that have no swass. Do you know what that means?” Alba said to Fallon. “I didn’t know. He said guys get sweaty ass, so his undies are no swass. I don’t know. I never knew that about guys.”

Fallon said he didn’t have that problem. “No, totally,” Alba replied.

The actress married Warren in 2008, and has two children with him: Haven, 5, who Alba said is starting kindergarten soon, and Honor, 8, who “never wants to wear pink, only wants to wear blue, and only wants to be sporty.”

Watch Alba explain Swass below.