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?
Person 2 "Meet me in the bathroom?"
Person 1: "See ya there..."