P.E tent
The act of getting an erection whilst in your underwear in the male P.E changing rooms at school; and getting caught in the act.
"Fuckin' hell lads, Dave's pitching a P.E tent! What a fag"
and
"HAHA he's got a P.E tent, gay boy, gay boy!"
and
"HAHA he's got a P.E tent, gay boy, gay boy!"