A slang term originating after two students were caught in a bathroom of a North Western Pennsylvanian high school having gay sex. To "get expelled" is to have gay sex in a bathroom.
Example One:
Person 1: knocks on bathroom door... "What the hell is taking so long man? I gotta go!"
Person 2: "Hang on bro, I'm getting expelled in here and it's pretty awesome!"
Example 2:
Person 1 "Hey there sexy, what do you say me n' you get together later and get expelled?
"now, if you twodon't mind, i'm going to bed, before either of you come up with another clever idea to get us killed - or worse, expelled." - hemione granger
"she needs to sort out her priorities." - ronald weasley