underpantsing 

To Pants someone but to pull there underwear down simultaneously weather purposely or on accident

Dude that kid got underpants in front of EVERYONE, they saw his junk and everything

Yo i was Underpantsing this and he punched me, It was a freakin accident i just wanted to pants him

underpantsing by Devon K May 30, 2008

underpantsgnomes

little gnomes that steal your underwear from drawers and even if you have them on!

The underpantsgnomes stole Billy Bob's underwear

underpantsgnomes by SaltyMcFog September 5, 2003