Jon Stewart and Jimmy Fallon Swap Pants on 'Tonight Show'

We finally get to see The Brotherhood of the Traveling Pants.

Jon Stewart dropped by The Tonight Show on Tuesday and rather unexpectedly dropped trou too. 

Stewart has been working the late-night circuit hard this week to promote HBO's Night of Too Many Stars special that raises funds and awareness for autism-related charities.

The segment opened with Jimmy Fallon talking about offering his pants as an auction prize for the special in tribute to his favorite film The Sisterhood of the Traveling Pants (parts I and II).  

Stewart considered Fallon's prize a terrible idea and wasn't persuaded even after the two late-night legends swapped pants. 

In case you're wondering, the real prize was two tickets and all an-expenses-paid trip to the Super Bowl. 

Night of Too Many Stars airs Nov. 18.