To punch someone in the undies. With your penis usually.
Me: How was your date last simo? Any undie punching?
Simo: Hell yeah, was awesome too. Plenty of undie punching to be had.
by Rodney Stewart March 13, 2008
Get the undie punching mug.
to be reamed unknowingly, usualy from behind while still wearing ones underwear. resulting in undies being stuffed into the oriface in question
i gave that bitch from starbucks a rightious undie punch..
she was all like

"AWWWWWW i say stop that young man dont punch my underwear into my date"

"captain to the bridge, there has been a royal undie punching on the lower deck"
by reg the great October 2, 2007
Get the undie punch mug.