Why would you call it pantsing? Because you're in idiot. If you pants someone, you are putting pants onto someone. While this would be an incredibly funny prank, i just don't see it being pulled off in a quick fashion. It'd be kind of a long drawn out process, which might make it even funnier. I'm not sure.
If you DEpants someone, you're pulling down their pants in public (as i'm writing this i can't believe people even do this. It's terrible. It really sounds like the meanest thing you could ever do to someone aside from falcon punching them) so as to cause maximum amount of embarrassment to the depantsee (person being depantsed) and cause 100% satisfaction to the depantser (person doing the depantsing).
Pantsing: putting pants onto someone as quick as possible without prior consent.
Depantsing: taking pants off of someone as quick as possible without prior consent (some people just pull the pants to the ground, but a true depantsing is all the way off. This is a very difficult maneuver and sometimes requires the subject to be unconscious, dead, paralyzed [with or without fear]. . . . . and this is starting to sound illegal.)
There are some key differences in the pantsing/depantsing debacle Obviously one is a little more frowned upon than the other. And also one may or may not sound a little bit like a precursor to rape (i do not condone rape). I only bring to light the differences because i know that if i had pantsed someone (put a pair of pants on them as quick as possible without prior consent), i definitely wouldn't want to be accused of depantsing someone.
Ted: did you hear that matt irving pantsed someone?
Florence: Oh, that is terrible. Matt is quite the scoundrel.
Ted: did you year that matt irving pantsed someone?
Florence: Oh, that is awesome. Matt is quite the hero!
Do you see how that might play out if people were confused? Yeah, it'd be terrible.
I'm sure a lot of you will argue that it's called "pantsing", but that's because you're stupid. Either that or raised incorrectly. Go ahead. Blame your parents. Blame them for teaching you that it's ok to say words that mean the opposite of what the word is supposed to mean, because it's not ok. It's disrespectful. It's disrespectful to your family. It's disrespectful to women. And it's disrespectful to America. Grow up.