debagging

(British & Coomonwealth) : The action of removing someone's trousers by force as a huiliation

British & Commonwealth slang): Remove someone's trousers by force to humiliate him, a popular practice among teenage boys as an initiation rite or a punishment for someone who has made himself unpopular. Victims are almost always male as detrousering can be regarded as symbolic emasculation. Traditionally most debaggings were carried out by males, but the presence of girls as onlookers or participants adds to the humiliation, and evidence suggests an ncreasing tendancy for girls to take the law, and the trousers, into their own hands. After the victim's trousers are removed they may be returned to him, thrown around while he tries to retrieve them, or placed in an inaccessible or public place.

pants pulled down and maybe underwear

Irish practical joke
To covertly acquire someones schoolbag, turn it inside out, replace the contents and return the bag to owner, without them noticing.
To really go for it, you can also turn their pencil cases, folders and even sandwiches inside out. When properly executed, there is no prank like a good debagging.
Warning: Debagging someone can trigger a wave of retalitory debaggings, which can trigger a full scale "debagging war" within the entire school. Some particurally epic wars have been known to go on for several weeks.
For the ultimate thrill, try debagging a teacher during class!!!

To have you area's exposed to the world

A generic Twitter user with a DeGod or y00ts profile picture. Bag biased.